Classic Motorcycle Mechanics ( PDFDrive )

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MIRA FILES The latest kit from Ian Saxcoburg’s CRK is for the early Hinckley Triumph triples. John Nutting rides his second prototype and finds he likes the new café society. 52 / classic motorcycle mechanics

WORDS: JOHN NUTTING PHOTOS: GARY ‘D’ CHAPMAN mechanics

MIRA FILES buying or even leasing a new bike. Its assembly is also fairly straightforward, because Ian provides all comes from the early series of machines from John the finished parts and an instruction booklet for their Bloor’s revived Triumph factory at Hinckley, which assembly. The only difficult process for some might this year celebrates its 25th anniversary. be the hacksaw removal of the original rear subframe. A benefit of this is a significant reduction Those early bikes had a real charm, with big in weight, and in the right places. All up, the latest chunky free-revving engines featuring common CRK Triumph weighs 198kg, or 436lb in old money, components mounted in a frame with large tubular which Ian reckons is a saving of at least 30kg, steel spine. By the time the Daytona came out a depending on the donor bike’s spec. That’s why the year or so after sales started in 1991, the CRK feels much more nippy. suspension, with a substantial front fork and an alloy rear swingarm using signature eccentric wheel Ian Saxcoburg has been producing his CRK café adjusters and linkage for the single shock, had been racer kits since the beginning of 2012, first showing brought up to date with ample adjustability. While his Honda CX500 special at the Classic Bike Show they were well regarded at the time, more than 20 at Shepton Mallet in Somerset. “My background is years on the lozenge-shaped styling of the plastic in engineering. I was trained with the Admiralty at bodywork looks not just dated but more than a little the testing establishment over in Gosport,” said Ian, bloated. In contrast, the CRK version feels fresh, 58, who is based near Ryde in the Isle of Wight. lean, mean and ready to go. Were it not for the fact “I’ve done the usual draftsman’s rounds of contract that the Hinckley factory has pulled off the master drafting. So I’ve got a bit of an engineering head on stroke of faithfully reviving the style of the old me.” He’s completed some very tasty restorations Meriden Triumph twins in a modern format, Ian’s over the years but then turned to making specials. “I creation could have easily emerged from the back saw a programme on telly from America in which a door at Jacknall Road. chap there had made a racer out of a CX500. The moment I saw it I thought it was such a brilliant I have to take another spin. This time I let it rip thing. But of course being American it had no and the revs rush up to 9000, and the sound is mudguards or anything like that.” almost like those BSA-Triumph racers from the Seventies. Controls are smooth and light, and the six-speed gearbox a marvel of precision: I dispense with the clutch and snap up and down the ratios, pretending I’m approaching and then accelerating away from the Ramsey hairpin in the Isle of Man. Better still, when I slam the brakes on after each run for photographer Gary, they respond without drama, and complement the grippy Michelin Pilot tyres to perfection. I can’t say if the CRK was a comfortable platform to have fun over an extended period, but I never found it the slightest bit irksome. It talked to me in a way few bikes have done. We got on well. Being a kit, the CRK Triumph can be so much more of an engaging experience than 54 / classic motorcycle mechanics

SPECIFICATION 1 ENGINE Liquid-cooled inline triple 23 IN DETAIL: 1/ CRK instrument cluster uses the original internals in a stylish assembly. 2/ The CAPACITY original exhaust pipe headers take slip-on Motad silencers, but others can be used. 3/ Radiator 885cc (76 x 65mm) cover promotes the Triumph theme, but customers can also do their own thing. VALVE OPERATION DOHC 4-valve per cylinder COMPRESSION RATIO 10.6:1 LUBRICATION Wet sump, 4 litres IGNITION Digital inductive CARBURATION Three 36mm flat slide CV Mikuni PEAK POWER 99bhp at 9500rpm PEAK TORQUE 64.4lb-ft at 6500rpm PRIMARY DRIVE Gear CLUTCH Wet multi-plate GEARBOX Six-speed INTERNAL RATIOS 2.73, 1.95, 1.55, 1.29, 1.15 and 1.07 to 1 FINAL DRIVE 630 roller chain FRAME Tubular steel spine type SUSPENSION Front: Telescopic fork, 43mm legs, with rebound and comp damping adj. Rear: Aluminium-alloy swing arm, single shock with adjustable preload and rebound damping FRONT WHEELS Front: Aluminium-alloy triple spoke Rear: Aluminium-alloy triple spoke TYRES Front: Michelin Pilot Road 120/70ZR17 Rear: Michelin Pilot Road 180/55ZR17 BRAKES Front: Dual 310mm Nissin discs, floating triple-piston calipers Rear: 255mm Nissin disc, single piston caliper ELECTRICAL SYSTEM Alternator, 60/55W headlamp, starter motor BATTERY 12v-14AH FUEL TANK 11 litres WHEELBASE 1490mm SEAT HEIGHT 790mm CASTOR ANGLE 63º TRAIL 105mm WEIGHT 198kg (436lb) dry www.classicmechanics.com / 55

123 THE BUILD: 1/ CRK prototype was based on this 900 4 5 Sprint Executive. 2/ After removing bodywork, the rear sub-frame cut off and replaced. 3/ Sub-frame as supplied: it doesn’t need welding. 4/ Rear suspension and swingarm are retained. 5/ Ian in his workshop. History of Ian’s CRK Triumphs The first orange CRK Triumph, which suffer from the ravages of ethanol. was first shown at the Shepton So a light-alloy inner tank is clothed Mallet Classic show in March 2015 within a fibre-reinforced resin cover and was used to prototype many of with the coolant header concealed at the parts offered in the kits, was a the front. Kits started to be sold from crash-damaged 900 Sprint the autumn of 2015 when the second Executive dating from 1996 bought prototype was started, using a 1994 for £300. So it is typical of the type Daytona 900 bought on eBay for £850. of machine that CRK customers This was used to improve the style of might obtain as a donor. some of the components. It is finished in pearlescent white and red, a Ian Saxcoburg wanted to fit a scheme that has proved to be popular long fuel tank that hugged the top with customers. of the engine, but one that wouldn’t / mechanics

“I’ve built a CRK Triumph café racer” He bought a CX500 for £100 with a plan to build Nick Vale lives near dealing with the inevitable seized a special. Then he realised that the engineering Reading and has fasteners you get on any 20-year- facilities that were once available aren’t there any been riding bikes since the 70s. old bike.” more, which is when he thought of offering kits. One of his many machines was “There’s lots of bolt-on accessories but there isn’t a Triumph Trophy triple 900 Nick sourced the silencers and anything where you can build a complete bike. So it bought new in 1992. It felt heavier indicators from CRK, new air and went on from there. I thought if I do all the tricky than the Ducati 851 he traded in crankcase filters came from bits, using my drafting skills and whatever to for it, but he loved that motor. Sprint Manufacturing, while the develop the brackets and things that you need then Last year a neighbour bought a correct lithium-ion battery was that means you don’t need a highly equipped 1993 Sprint, and during a ride found online. Paintwork for the workshop to build yourself a bike. You can do it in they swapped bikes. The Sprint tank, seat and wheels was dealt a garage like a kit car.” recalled memories of his Trophy, with by Revolution in Reading. “the gorgeous engine, rubbish The exhaust downpipes received It was later in 2013 when one of Ian’s later weight distribution and a matt black coating from CX500 café racers was being tested for CMM that he surprisingly good handling”. Zircotec in Abingdon. revealed his plan to offer a kit for the early Hinckley After reading about the CRK three-cylinder Triumphs. By then the CX500 kits kit, Nick thought it looked A trip to Dynotech in Bramley were selling well with customers in Australia, New beautiful, but it would also solve enabled the carbs to be sorted to Zealand, South Africa, America, Europe, the top heaviness of the original. perfection on the rolling road. Scandinavia and even Iceland. “Not bad for a bloke He ordered a kit and began “She now runs really sweetly working in his garden shed,” quips Ian. The logic of looking for a donor bike: “I finally with a flat torque curve from offering a Triumph kit was undeniable. With a donor found a 1994 900 Daytona, with 6000 to 8000, peaking at 57lb-ft, machine available for as little as £300, a very shabby bodywork and lowish and at just under 9000rpm there’s presentable café racer could, with the kit costing mileage for £1095.” over 90bhp at the rear wheel. around £2000, be built for less than £4000. The bike had been a Cat-C write More than adequate!” One small off and problems had included a problem was the chain fouling The kits include a new rear subframe, a light-alloy poorly assembled Suzuki front the new subframe, which Nick 10.5-litre fuel tank with glass-fibre reinforced resin brake assembly, and a seized rear suggests was possibly due to the cover, front mudguard and a seat moulding that caliper. A £200 front wheel, discs width of the Daytona rear wheel covers the battery. Other components include clip-on and caliper corrected the front – she’s running a 180/55 section handlebars, rear wheel hugger, chainguard, end while Powerhouse rear tyre – but that was easily instrument console (taking the original internal Automotive refurbished the sorted by a judicious use of angle components) and lighting equipment. Objective was caliper for £70. “When Ian’s kit grinder. “Other than that she’s to lower the weight and profile of T300 triples such arrived the stripdown was been a total joy to own and ride. as the Sprint, Daytona, Trident, Trophy and Sprint straightforward but cutting off The pipes have a fruity growl at Executive made between 1992 and 1996. the rear subframe was the low revs that morphs into a scariest part, although Ian’s wonderful banshee howl above “Work started on the Triumph project in February instructions were very clear and 5000rpm. She’s actually more 2014,” says Ian. “It has involved a lot of design easy to follow. All his parts fitted comfortable for me than the work on the computer after making digital just so. It took me a couple of original Daytona, and always gets measurement the donor bike. The metal parts have months to complete the strip admiring looks whenever I pull all been designed using 3D CAD software and the down and build, working on it over for fuel, which is about every glass-fibre parts have more ‘artistic’ input to get maybe 10-20 hours a week. I think 80 miles. But as I’m not planning the final shapes.” the most difficult part was to tour on her, that’s not a problem. I’ve got a unique and The reason for using an inner light-alloy tank is to very pretty bike for about £5000.” eliminate ethanol fuel problems. The smaller size also allows the coolant header tank to be hidden Nick Vale’s tidy take on the under the cover. The original exhaust pipe headers CRK Triumph – just like Ian’s. are retained to which customers can attach their own choice of silencer. Ian can supply the Motad reverse-cone silencers used on the white-and-red machine. Air filters and suitable jets are supplied for the Mikuni carburettors on the earlier bikes and the Keihins used after 1994. So successful has the venture been that by the end of April, Ian had sold almost 50 of the CRK www.classicmechanics.com / 57

What are Hinckley Triumphs? The original Triumph factory at specialist Les Harris in Devon. By Meriden in the Midlands went 1987, a new 1200cc four-cylinder into decline in the early 1970s Triumph ran for the first time after manufacturing problems then in late 1990, a new range of had hit sales after the BSA- Triumphs was launched at the Triumph group was acquired by Cologne Show, with production at Norton-Villiers. the new Hinckley factory starting in 1991. The range comprised the The company planned to close unfaired Trident 750 and 900 Meriden, so workers there went Triples, the touring Trophy 900 on strike, formed a co-operative Triple and 1200 Four and the with government support and sports-oriented Daytona 750 limped on until 1983, when the Triple and 1000 Four. factory finally closed and the rights to the name was bought by Since then Triumph has builder John Bloor. Bloor set up a diversified its range into sports- small factory at Bedworth where orientated triples, shaft drive development of a new range ‘big’ triples, adventure triples began. Triumph Bonnevilles and the traditional parallel-twins, continued to be made in small which have recently been number under a licence redesigned to better recall the arrangement with spares style of the Meriden machines. m / mechanics

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RETRO WORDS AND IMAGES: KAR LEE 60 / classic motorcycle mechanics

he id-80 as a thrillin im THE ORIGINAL al roun e K . ki h un ENGINE , a CHASSIS ,s BODYWORK . ,y . m What do you think? Is this the bike Yamaha should build? Let us know! www.classicmechanics.com / 61



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The Shed... New parts for your bikes, parts on test and the top tyres of the time: you’re in The Shed. Clutch conundrums solved According to a recent survey by Venhill, clutches. Let’s leave this here… what with nearly half of motorcyclists with a Brexit I’m sure we’re all bored of hearing cable-operated clutch believe that about votes and percentages! Instead, let’s replacing the cable would improve its ask Max Adams of Venhill. He said: “One performance and 40% of them would of the simplest and most cost effective consider upgrading to a hydraulic system. ways to improve clutch feel and action is a straight swap of the OEM cable to an Well I never. Venhill asked more than upgraded version. 350 riders and while the majority of bikes had a traditional cable-operated clutch, a Developed by Venhill, Featherlight significant minority (37.5%) were fitted cables deliver improved performance and with a hydraulic system and their owners durability as well as a much smoother were much more satisfied with the clutch action. Made with Teflon liners and operation. A total of 48% described it as stainless steel inner wires, they are light/smooth, compared to 32% of cable virtually maintenance free. They’re also ‘bird-caged’ – a special process applied to the end of an inner cable wire that allows span adjustment for extra comfort and solder to penetrate the weave of the cable control, they are also self-adjusting, so – making the bond with the nipples/ends they need considerably less set up and much stronger. maintenance than a cable. Made in the UK, Featherlight clutch Hymec kits come filled with a specially cables look to be good value: check out developed mineral oil – Magura Blood – www.venhill.co.uk for further details. which is non-toxic and non-hygroscopic, so won’t it need changing as frequently Venhill can also help riders wishing to as regular brake/clutch fluid, and isn’t upgrade to a hydraulic system as they are harmful to health or the environment. Kits the UK distributor for Magura Hymec kits are available for many road bikes and from Germany. Engineered to make clutch prices start at £260.90 including VAT. operation 20% lighter, with improved feel ■ Call 01306 885111, or head to the and control, they eliminate ‘fade’ and help Venhill website for more. to reduce fatigue. Supplied with a forged lever, which has improved ergonomics and Apply the perfect pressure Funnel of love! We’ve just got hold of this to asking if we wanted to test a Wunderlich’s Folding Oil Funnel makes filling up test at CMM. Now, many people pressure washer of theirs. “No with fluids a lot less messy. will tell you that you shouldn’t need,” said I, “I’ve already got use a power washer on your one and it works just fine.” But Topping up engine and transmission oil in the bike, but I have for the last 25 they pushed, prodded and workshop, or out on the road, can be a real test of skill, if years and never had an issue. cajoled and sent CMM an you don’t have a suitable funnel. Made of a flexible oil- With that in mind, Bosch Lawn AQT-37-13 to test. I had no and petrol-resistant material, Wunderlich’s folding funnel and Garden gave us a call idea what it was either, but it helps get the fluid where it should be, instead of all over says in the press blurb that it your fingers, the bike’s exhaust and/ has a “powerful 1700 watt or the floor – reducing mess and motor” and has a “space-saving waste. Taking up little space when design, with sturdy wheels and folded, the funnel can be wiped clean an easy-fold handle”. Personally and stashed in a tool box/roll or I’m just hoping it can shift the under the seat ready for whenever crap off my various project it’s needed next. It can also be used bikes and rip weeds out of my for topping up with petrol. block-paved drive… ■ The Wunderlich Folding Oil Funnel ■ Price for the washer is costs just £6 including VAT, and is £159.99 and £179.99 for the available from exclusive UK added accessories kit with the distributor www.nippynormans.com patio cleaner. 64 / classic motorcycle mechanics

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Little FZRs are little gems... Our very own wizened sages, 1968 Honda Messrs Mark Haycock and CD175 Sloper Q:Yamaha FZR400 Steve Cooper are here to I have come across a Yamaha answer all of your woes, be Q:I am having trouble finding a FZR400 which appears to have replacement battery for my been sat in various sheds for a number they mechanical or spiritual. 1968 Honda CD175 (Sloper). I of years. However it has no V5. One Every month we will be giving believe it should be a Yuasa B41-6. reason is that somewhere down the line advice as well as some general However this seems to be no longer it could have been stolen which is my tips. Don’t forget to send in available. Could you please advise on main concern. a suitable alternative. Many thanks. your own tips too. It would make a nice project but 1980 Honda CB750F Phil Chamberlain opinions vary online from ‘keep away’, to ‘I have bought many bikes without Q:Supersport. A:I used to have one of those, V5s and had no issues!’ I’m building a Honda CB750F and I wish I still had it. That supersport US import from 1980. battery was available as a Honda Mick Pykett Now, I’ve rebuilt the frame, turning it into spare part (31500-230-020) but of a hard tail bobber. I have sourced a new course it was deleted long ago. Yuasa A:My opinion is to look around for engine for it and I am going to rebuild the have changed their identification another where the owner (or should carbs. The carbs are CV carbs, and I have codes, so that is why you will find no I say, keeper) has had the common sense heard and seen on many forums that these reference to the original B41-6. and been organised enough to either keep carbs don’t work well with a custom Unfortunately, I have no cross- hold of important documentation, or work exhaust with cone filters, or pods. How can reference between ancient and out how to get a duplicate from DVLA. I sort this out to make it run sweet and modern but the original unit was rated smooth? What do I need to do? Any help? at 6V-10Ah and the terminals were If that is not the case then the obvious both on one side, so these are the assumption must be that the owner Thomas Gavin main requirements apart from being cannot get the duplicate because bike small enough to fit in the housing. has been stolen. A:How to make it run properly? Oh, In fact, as no starter is fitted the that’s easy: put on the original capacity is probably not that critical. Why bother taking the risk and messing exhaust and air filter. Okay that is not about negotiating with DVLA when there an option, is it? You will have to either I think you will not find a modern are lots of other projects out there? replace the carbs with something else or battery with the breather pipe find the best settings for the various jets positioned in the middle of the long within the current carbs, and find the best side like the original, but I am sure settings for ignition timing. The question is you can work your way round that. how to do that and you have several options You might use a modern sealed unit open to you. The first thing is to ask the (which of course would not need a manufacturer of the new exhaust what they breather) but it would probably be recommend as one would like to think that unwise as the charging system is not they have actually tested their product to very well regulated. I suggest you take a look at Yuasa’s current catalogue as there is quite a range and they give terminal layout, voltages, capacities and dimensions. You are bound to find what you need there. If necessary, you can get one slightly smaller and use rubber to pad it out to make it fit. ensure it can work properly and how best to make that happen. Otherwise you could keep on searching the forums to find if someone has a similar combination of mods and has already done the research for you, generally fiddle about until you hit upon the most successful combination or spend some time and money in employing an expert with a dyno to use their expertise. Send your queries to: [email protected] or write to Problem Solver, CMM, PO Box 99, Horncastle, Lincs LN9 6LZ 66 / classic motorcycle mechanics

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Following on from my part 3 Brake bleeder: handy! basic engine service a few months back, this Basic maintenance issue we’ll tackle changing Serial bike buyer and maintainer Andy Bolas takes your brake fluid, changing us through a basic fluids and coolant change and your coolant and also the balancing of carb balance. four-stroke carbs. Firstly, we will tackle changing brake the tube connected to the nipple, slowly have removed all the air from the system fluid, which sometimes is neglected, release the bleed nipple until fluid starts (the tubes are clear so you can see the causing problems later on in the bike’s to come out, pull the trigger on the brake air bubbles). braking system. To change your brake bleeder (this creates a vacuum and sucks fluid, ideally you will need a brake bleeder the fluid out) making sure you keep the When you are satisfied the fluid is clean similar to the one in the picture, which fluid topped up. If you allow the reservoir and contains no air, lock off the bleed will cost around £35-£40. It makes the to run dry this will introduce air into the nipple. Before you refit the seal and cap, job safe and easy to carry out on your own. system. If this does happen don’t panic: top up the fluid until it’s above the lower So let’s get stuck in! First of all, remove carry on bleeding as before until you level mark on the sight glass, then give the lid to the front reservoir/master cylinder, them a wipe over and check the condition making sure to use a decent screwdriver as And the seal under cap. of the seal. If the seal is damaged it is these screws are often not the best and be best to replace it, as fluid may leak and careful with the seal. Make sure you don’t Connecting the brake bleeder to the damage any surfaces it comes into contact drop any brake fluid on your paint work, as bleed nipple. with. You will undertake the same process brake fluid loves paint. It’s best to cover any for the rear although you may need to areas of the bike which are exposed with an remove a small amount of bodywork to old sheet or blanket. locate the reservoir as it’s often hidden Now locate your bleed nipple/nipples away out of sight. (I always make sure they are free before connecting the bleeder; make sure you The front calipers on this TDR250 bled have a rag handy at this point as some fine with no issues, however the rear fluid may come out). You now need to caliper’s lower bleed nipple was blocked make sure you have your brake fluid open and would not allow fluid to pass, so a and ready to top up the reservoir. So with couple of dabs on the rear brake pedal forced a bit of muck through and then Removing the screws from the master normal service was resumed! cylinder cap. To change your clutch fluid, follow the Removing the cap and seal to show the same procedure as above again being old-dirty brake fluid. careful not to spill any fluid! Now here’s a handy tip: if you find your lever a little on the spongy side, try tying the lever back to the bar overnight. This will help to expel any trapped air from the system. So why do we need to change our brake/ clutch fluid? Well, over time the brake fluid will absorb water, which will cause corrosion and in extreme cases can cause brake fade and also lead to sticking/seized pistons. This is due to the fluid being 68 / classic motorcycle mechanics

Don’t overtighten lock-off bleed nipple. Multi-tasking Bolas, bleeding while maintaining the fluid level. Clean and inspect seal before refitting. Fresh fluid filled to the correct level. Location of rear reservoir on the TDR. Remove seat and side panel to access rear reservoir. hygroscopic which means it absorbs Remove reservoir to improve access. moisture, which will lower the fluid’s Bleeding while topping up reservoir. Dirty old fluid in rear reservoir. boiling point. The generally recommended interval for changing brake fluid is every Fresh fluid in rear reservoir. two years. www.classicmechanics.com / 69 Next up, we tackle a coolant change, so first of all a little warning which I will put in capital letters so you can’t say you haven’t been warned! DO NOT OPEN OR REMOVE THE RADIATOR CAP IF THE ENGINE IS WARM – YOU MAY GET SCALDED! ONLY REMOVE THE CAP WHEN THE ENGINE IS COLD! There, I’ve said it. Now locate your radiator cap, expansion tank and your drain point. Here, on the R1-Z we are working on, we first need to remove the seat and fuel tank. The radiator cap is (surprise, surprise) on the top of the radiator (on some bikes it’s on a neck, away from the radiator). The expansion tank is under the fuel tank and the coolant drain point is located on the right hand side of the engine on the water pump cover. You can now either remove the pipe that feeds into the radiator from the expansion tank, or do as I did and drop the coolant straight from the drain point on the water pump into a suitable container.

SUBSCRIBE TODAY SEE PAGE 34-35 FOR DETAILS TOP TOOL TIPS • CLASSIC REVIEWS • PROJECT BUILDS Rear reservoir cap and seals. Radiator cap in position. Water pump cover with drain bolt. Expansion tank location. First, remove drain bolt. Drain coolant into a container. Refit drain bolt with new sealing washer. When the expansion tank is empty then coolant change, we need to remove the Fill radiator with fresh coolant. remove the radiator cap and drain the fuel tank to gain access to the vacuum remaining coolant out in to your container take-off points on the carbs this time. with the bike slightly inclined to the right Now, I have never balanced a set of to assist in the draining of the full amount four-stroke carbs before so was happy of coolant. Place the bike back on its when my mate Keith said he would go side-stand and replace the coolant drain through it with me and also let me use his plug, ensuring that you change the carb balancer! Although now having done sealing washer. Fill the radiator with the job, I wouldn’t mind investing in a set coolant (I use Motul pre-mixed coolant myself as they worked very well. but any pre-mixed coolant will be fine), replace the cap then fill the expansion So, as you can see in the picture we have tank to the upper level. gained access to the carbs and the vacuum take-off points and connected a dummy Why do we need to change our coolant fuel tank. Now the pipes from the balancer then? Well as with brake fluid, over time are labelled 1-4 and these are then coolant can get contaminated and may connected to the corresponding cylinder’s become acidic. When this happens its carb. With the balancer switched on and ability to cool the engine is reduced. The the motor up to working temperature we recommended interval for changing can begin. You can see from the picture coolant is every two to three years. I then how far out of balance the carbs on my connected a dummy fuel tank up so I 1200 Bandit are, as these black lines could run the bike up to operating should all be level. temperature. With the bike at operating temperature, I allow a few moments for To adjust these, you will need to locate the coolant level to settle, check the the adjusting screws. These are usually level again in the expansion tank and located on the throttle linkage, one top-up if required. between each carb. The left-hand screw synchronises the carbs to cylinders one Last, but not least, we synchronise a and two, the right-hand screw bank of four-stroke carbs. As with the synchronises the carbs to cylinders three Before fitting radiator cap check seal for Top up expansion tank. Check level after running up and top up damage. to full if needed. 70 / classic motorcycle mechanics

Carb balancer: very handy! Cap on vacuum take off point. Here we can see the Bandit 12 carbs exposed under the tank. Vacuum take-off with cap removed. Balancer connected to the vacuum take-off. and four. At this point Keith told me it’s always best to bring the longer line down How far out are these carbs? Adjusting the screw for balancing. to match the shorter one: then when you have balanced both pairs of carbs use the Using Inner and outer adjuster screws. Using the centre screw: sorted! centre screw to bring them both inline. At this point you may need to adjust your idle speed accordingly. Blip the throttle a few times to ensure that when the motor settles to idle the lines are still level. When you are happy with the settings, remove the pipes from the balancer and refit the caps, not forgetting the vacuum tube on number three carb as this connects to the fuel tap! Remove the dummy fuel tank and refit the fuel tank along with any other bits of bodywork you may have removed to gain access. So why do we need to balance our carbs? Well, poorly balanced carbs can cause a number of problems including higher than normal fuel consumption, poor throttle response and even vibration and engine noise. Next time up, we tackle a brake service and pad change. cmm ■ Thanks to Keith Brindle @ Chase Superbike centre 01543 466416 for the help and loan of the tools! www.classicmechanics.com / 71

Project Yamaha TX500 part 3 Fuel’s gold WORDS AND PHOTOS: MARK HAYCOCK He’s sorted the filter then, but what about the fuelling on Mark’s TX500? 1 One area which needed places. So almost certainly polishing will as the vacuum will eventually stop the fuel cosmetic attention on not be sufficient. flow. Finally, the cap needs to allow only the TX500 I bought the owner access to the inside of the tank was the fuel tank, which had Although it seems simple enough, when as thieves might take the fuel out, but been damaged by leaking you think about it the fuel cap has to worse than that, naughty kids might be petrol (Photo 1). achieve several objectives. Naturally it tempted to put something else in. It was a pity that this had not been dealt needs to stop the fuel from leaking out in with as soon as the leak had become liquid form, as this is dangerous and So it is all rather less simple than we apparent as most of the paintwork on the wasteful (as well as knackering paintwork). might have first imagined, as we shall see. tank was perfectly okay, apart from the It also needs to at least cut down if not By the way, this design of cap was also area around the cap. I have not thought prevent evaporation, as that must result fitted to a number of other contemporary yet what I am going to do about this, but I in the lighter fractions of the fuel Yamahas such as the XS500, TX750, XS1, would like to save the original paint if disappearing, resulting in more difficult XS650 and RD250/350. possible. I am not sure whether this will cold starting. be possible as it is not just a dulling of the The cap itself is quite separate from the lacquer – a closer look shows that the One interesting point is that this must locking mechanism and is simply removed colour seems to have been washed out in be achieved while also allowing air to by taking off the world’s smallest e-clip enter: when the fuel is used up the empty (Photo 2) and if you can, not losing it. space needs to be filled with something Then pull out a 3mm diameter pin and 234 1/ Leaking leads to a damaged tank. 2/ If you know of a smaller e-clip, we want proof... 3/ Damage is plain to see here. 4/ Cap broken down into constituent parts. 72 / classic motorcycle mechanics

Simple solutions: Don’t lose small parts: bag them up immediately. 567 5/ This is how Mark thought these pieces first went together. 6/ The ‘funny’ washer seemed the same diameter as this seal. 7/ Eventually, this sub-assembly was made. Are you keeping up? 8 9 10 8/ When inverted, the assembly sat on ‘this silvery thing’ as Mark describes it! 9/ These cut-outs match the bumps on the seal. 10/ Turn this over and you can now fit the bigger seal on the rim. straight away we can see what the problem which exactly corresponds with the wider Now we have this sub-assembly (Photo is (Photo 3). Fancy letting it get to this part of the seal at the top in this picture. 7) which, when inverted, fits on to the stage – but there we are. Fortunately the The funny washer seemed to be the same large silvery thing (it doesn’t seem to have seal is available from Yambits, though diameter as this other seal (Photo 6), and a Yamaha name) shown on the right hand actually it is part of a kit comprising the would fit inside it. You can see that the side of Photo 8. The left hand component three seals shown on the right hand side. washer and the seal each have a tiny hole, is the part you can see when the cap is and thus it was obvious that the holes opened, and notice the corrosion which I think you can see that the assembly is should line up. Except that the washer did afflicts it as a result of years of storage. held together by a normal-sized e-clip and not seem to fit properly and then the having taken it off we can see the separate penny dropped: the holes should not line You can see the central hole has three parts (Photo 4). What I have not shown up but rather be as far away from each tiny extra cutouts which, would you believe here are the remains of the smaller seals other as possible. The reason? These holes it, exactly match the curious little bumps which had been reduced to something like must be for either pressurised fuel vapour on the seal so this shows how the two big black chewing gum. This meant that to escape when the bike is parked with a metal parts are assembled (Photo 9). reassembly took a little detective work as I hot engine, or air to enter when it is Turning this assembly over, we can now fit could not tell which way round the seals running – but not allow fuel to leak out. the big seal to the rim (Photo 10). Now it were supposed to fit. The seal forms a somewhat tortuous is just a case of dropping the spring on the passageway which achieves that objective. central peg on the underside of the cap Anyway, the following is what I managed This was confirmed by a closer look at the (Photo 11) and fitting the big e-clip (Photo to work out. We start with this odd-shaped seal which had two little projections inside 12) and the cap is complete. washer and the smaller seal, which which would then align with the cutouts in evidently went together like this (Photo 5). the washer. To fit the cap, all you have to do is to I say evidently because there is a so-called push in the 3mm pin and fit the tiny ‘witness mark’ i.e. an area on the inside e-clip to the end. You will see that it was much easier to take off than to fit. 11 12 Anyway, after several attempts at fitting the e-clip you will find that it has 11/ Time to drop the spring into the cap and get ready to put the sub-assembly in. 12/ And suddenly completely disappeared so finally the assembly is complete! what next? My solution was an M3 x 30mm round headed cap screw and an M3 Nyloc nut, a combination which looks okay and is considerably easier to fit. The chrome on the cap is pretty good and it does not leak now, so all I have to do is to sort out that paintwork on the top and retouch the Yamaha badges on the side… and the list goes on. Except that soon I shall be able to get the engine running: an exciting moment. Or disappointing. Which will it be? cmm www.classicmechanics.com / 73

ThTeimFires…t Niall Mackenzie goes back in time and picks up a version of his very first two-wheeler. Project Honda C70 part 1 WORDS AND PHOTOS: NIALL MACKENZIE Most of us can still It could barely propel it’s own weight, recall that never mind a chubby 13-year-old no incredibly liberating matter how hard he twisted the throttle. and possibly life changing My very first bike journey however, was as moment when we rode a a pillion passenger with a bloke called motorbike for the first time. Mine involved Tosh. I never knew his full name but his a Raleigh Wisp pottering along the Carron surname would definitely be Mackintosh Grove Paper Mill railway line after it had as everyone with this name in Scotland been rescued by friends from a local gets called Tosh. Tosh had a grey Honda scrap heap. C50 and rescued me from a skirmish with kids from our neighbouring village when we attempted to set their A youthful Niall bonfire alight one year on November back in the day. 4 (…you meet the nicest people on a Honda, eh Niall? Bertie). We only travelled half a mile on paths and lanes but it was an amazing feeling, even if I kept trying to lean in the opposite direction when he banked into corners. I still bear this in mind when I do race day pillion rides at the BSB rounds. I can’t imagine how scary it must be flicking through Craner Curves at Donington Park on an R1 when you’ve never even sat on a motorcycle before. And that’s where this story really begins. The C50 and Wisp experiences got me totally addicted Overall, not bad. 74 / classic motorcycle mechanics

Spot the original, anal owner. Pipes always an issue. and in pursuit on my very own motorcycle. abused them to see which machine would it is the most hideous colour ever. I didn’t have to wait long as my friend Jim last the longest. I chose a C70 and it is Weather-beaten but solid is the best way was selling his C90 to raise an HP deposit the sole surviving member of that mental to describe my P-reg acquisition and with for a new Fizzy. Forty quid changed hands feature and is running now like the day it only 19,000 miles on the clock I suspect in the summer of 1975 and (unbeknown left Japan. this motorcycle will still be running when to me) I then owned an icon, take a look I’m in a box. With an above average at the picture to see the Old Trout back I still enjoy riding these bikes so I amount of surface rust in evidence I in the day! For skint teenagers in the thought why not dedicate my first non assume this bike has lived mostly Seventies these bikes were perfect. two-stroke, non-Yamaha restoration to my outdoors. The plastic leg guards and front first ever biking experience. My TWO C70 mudguard have faded into a multitude of No matter how hard you raced, wasn’t an option as it has no V5, so after colours while the exhaust, headlight rim motocrossed or jumped them they much trawling on eBay I found bikes in and wheels are more orange than chrome. wouldn’t break. Fuel and Elastoplasts was varying states randomly priced between The paintwork and engine cases are also all that was needed to begin honing the £200 and £2000. The supply and rough but very refurbish-able. Thankfully rudimentary riding skills that last a demand seemingly goes in waves and though, the rear mudguard which is lifetime. My C90 would also transport four prices fluctuate accordingly so I kept normally first to rot and tricky to replace people and pull sledges when the snow placing max bids and sitting tight. It took is in great shape. came. Memories of this sweet little a few months but eventually my patience machine first returned around eight years was rewarded when I won me a newly- I know at least eight riders in the BSB ago when my Two Wheels Only magazine MOT’d mustard 1975 C70 from a kindly paddock who have customised Honda editor at the time, John Cantlie, gave five pensioner in North Devon. Cubs (seriously) and every one of them staff members £200 each to buy a looks great. Most lose the plastics to show motorcycle. The deal was we then totally At £350 and with six previous owners in bare frames before reupholstering seats, 40 years I definitely wasn’t robbed even if www.classicmechanics.com / 75

Love or loathe this bit? It promises to be quicker to sort than the RD. slash cutting exhausts and adding funky Everything coated with paint is in good Mike Skinner from Skinner Motorcycles paint jobs. Buildbase BMW rider Richard condition so I’m hoping it will be a Dundee told me I need to mix equal parts Cooper and his buddies van them over to straightforward process of prepping and malt vinegar and cheap cola in a plastic the IOM TT and use them as runarounds powder coating these parts. The major tub. Insert two screwdrivers then connect on the Island over race week. And I saw chrome work is a different story so I them to a battery charger. Switch on and plenty more parked up on Douglas Prom suspect replacing wheels rims, spokes Mike reckons in no time you’ll have last year, which for a brief period inspired and the exhausts will be cheaper than thoroughly cleaned carbs outside and in me to attempt building a special of my re-chroming. There is no need to strip with no residue. own. Fortunately, soon after my moment the motor so I’ll be powder coating the of delusion, I remembered I was no outer cases and freshening up the On second thoughts I might get my Roland Sands or IDP Moto, so a standard crankcases, cylinder and head which boys to try this first time round while I resto it will have to be. are still in nice condition. stand outside. It’s just great to get a new project on the bench so with I will however be ditching the yellow for Cleaning the carb outside and inside is spanners at the ready it is time to the grey of my original 1975 bike. The something I’m particularly excited about. get busy. I’ll be reporting back on next job then is to take her to bits. Just listen to this for a recipe! Good friend this one very soon! cmm Nurses swore by ’em. Not in bad nick. Enclosed loveliness. 76 / classic motorcycle mechanics

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Project Yamaha TZ250 S part 3 WORDS & PHOTOS: JAMES WHITHAM Stroker Ace! Yes, James Whitham on the subtle nuances of the racing two-stroke! Most people who get The dodgy ones lock up solid or jam on tyre a gearbox oil marinade. This, by involved in restoring full throttle just as you’re about to tip into rights, should’ve resulted in his chalky old a road bike have an a corner! Mick Grant was launched down bones shattering like glass, but thankfully, interest in riding it when it’s the track at 80mph during the Imola 200 even at 70 years old, Mick is still as tough finished, (even though most of festival in Italy a couple of years ago when as an old miner’s boot and he limped away us never ride it as much as we promised the RG500 Suzuki he was parading blew from the scene in one piece. ourselves we would) so they take care that the sprocket seal out and gave the rear all the running gear and engine internals Tight northerner photocopy. If your intention is just to hang it on are in as good an order as the paint and your wall and look at it then no problem, chrome work. but better for me that a bike is as nice on A lot of people who tackle a race bike the inside as it is on the outside and even restoration though (even some of the ones this can’t guarantee your safety as we all who do it for a living) assume that the bike know that an old ring-dinger can still bite will never be run, but rather it’ll be added you on the arse! to a collection or parked in the corner of an office ‘because the MD raced one these I’ll stand by my statement in a previous in the 70s!’ So they make the shiny bits issue that a racing machine is a simpler look mint but don’t worry too much about It even covers how to ride it... the spinny-go-around bits. I’ve raced and paraded loads of old bikes that worked really well... but I’ve ridden as many that have been dragged out of a museum or someone’s living room the day before and meticulously prepared by sloshing in some fuel and giving the chain a squirt of lube. Unsurprisingly some of the latter group pooped themselves after half a lap. And the ones that just stop are the safe-ish ones. 78 / classic motorcycle mechanics

The TZ250 S is really starting to come together. A race bike is simple and neat. device than most road bikes and therefore help you with all this is a copy of the sparks because CDI units and coils tend to easier to restore. But if you’re rebuilding a original manufacturer’s service manual. look the same regardless of whether they’re racing two-stroke with a view to riding it, One came with every new TZ. They were good or knackered. you need to put it together more unbelievably comprehensive, even (under accurately, with more regard for tolerances the heading ‘control functions’) telling you The electrics on the S are odd at the and settings when it comes to engine how ride your new racing bike, although best of times. The actual ignition is a internals, torque values, carb set-up, I’m thinking that if you needed to read this basic, self-generating capacitor discharge ignition timing and exhaust pipes. section, you may well have been biting off system similar to what you’d find on most slightly more than you could chew… Most bikes of that era, but the powervalve If you try, for example, to run a racing manuals have been lost over the years so system is total loss, taking it’s power from two-stroke with too tight a piston skirt they’re now very rare and consequently a rechargeable battery pack that sits inside clearance, it’ll seize, or with too small expensive. I called Clive Padgett (the boss the fairing. The ignition system triggers carburettor jets for the prevailing at Padgetts motorcycles) to ask if he had the powervalve servo at a given RPM (in conditions, it’ll seize. With the wrong one for a TZ250 S and he said ‘of course’, this case 7500) and the battery powered piston to cylinder head gap (squish I asked if I could borrow it and he said servo then opens the valves in the exhaust clearance) it’ll eat away the outside of the ‘no, but you can use my copier to make ports via cables. piston crown (known in the trade as yourself one’. Two hours, a ream of paper ‘detonation’) then seize. With the ignition and a bleeding index finger later and I had Obviously a 30-year-old dry-cell battery timing set wrong it’ll seize and/or hole the all the tech info I’d need! ain’t gonna be much use, so I dropped the piston. With a crack in an expansion old one in at a model car shop. The boys chamber it’ll… yes, you guessed it, it’ll The four main aspects of the rebuild there are dead good with batteries and seize. Anyway, you get the picture, right? where the manual came in handy was all made me up a new one to the same spec the torque settings, the ignition timing, as the original, using the old block This is one of the things I love about how to check every ignition component, connector. The only real problem was that high performance strokers: they almost and how to set up the powervalves the modern cells they used are smaller have a character. To get the best out of accurately and in sync with each other. physically than the old ones so I had to them you have to understand how your The ignition timing is set static using a dial pad out the battery housing in the fairing bike works and tinker accordingly! If gauge to determine TDC (top dead centre with a bit of foam so it didn’t rattle about. you do everything right it’ll love you of the stroke i.e. when No. 1 piston is right right back! What’s needed actually to at the top). Ignition parts are checked one The bike is very nearly finished now. I at a time using a simple multimeter type just need to go pick up the bodywork device. Without being able to do this you’d from the paint shop and mix some fuel struggle to trace the problem if you had no and she be ready to make some smoke for the first time in 20 years! Anyone fancy a sniff? cmm Here are the Powervalves’ housing... ...and again here. Here’s where the Powervalve servo sits. www.classicmechanics.com / 79

This for £100. Bargain mate... Project Honda VFR750 F-R part 2 Hundred pound hound He umms, he arrrs, but will he actually get anything started on the Hundred Pound Hound? Oh, and the GPz while we’re at it?! Ifully expect to be times are hard. Sometimes we pay full Forks will be reworked, stoppers were admonished, told off and whack. We all understand that. But for never the best. Upgrade? otherwise b*llocked by you, some reason the Hundred Pound Hound dear readers, but I’ve finally has caught some of CMM’s advertisers’ worked out what I’m doing (and non-advertisers’) imaginations and with both this, Project Hundred Pound many have just sent bits and pieces Hound and the GPz. off-spec, without any prompting from me. The thing is, with the GPz900R stripped and me being in a quandary about whether With the bike being so cheap I’ve had a it should be an update or just a straight few bits and pieces thrown at the project retro, something made up my mind for me which has made me realise this can’t be a and that was this, the Project Hundred standard restoration. The lovely people at Pound Hound. Performance Parts Ltd sent some LSL First of all I’m going to be honest – and levers for the VFR, front suspension many bike magazine editors/journalists are springs and chain and sprockets, all not. Being lucky, those that write for CMM unbidden I hasten to add! Throw in a YSS and other motorcycle magazines get the Z-Series rear shock from Wemoto and a odd chance of some free bits and pieces. superb deal on a sexy GPR end-can and Now, having been in this game for more the writing was on the wall: Project than 20 years, more often than not, Hundred Pound Hound was going to have today’s economic climate means often the to be a bit of a special, but how special? best you can do is get a trade deal on some parts because money’s tight and In typical me fashion, at first I thought that I should start throwing wads of cash at the VFR and go for a big-bore kit, with 80 / classic motorcycle mechanics

SUBSCRIBE TODAY SEE PAGE 34-35 FOR DETAILS TOP TOOL TIPS • CLASSIC REVIEWS • PROJECT BUILDS Gear lever needs replacing or tidying. Rearsets will replace pegs, pillion hangers to go. Old Venom can has to go. If anyone wants it, make me an offer! new bodywork to make an RC45 replica or New GPR is sexier by far! This allied to a stage one tune is all I will do. Who needs even an NR750 replica: check the more than 100bhp really anyways? interweb, there are a few about. Then I calmed down when the meds kicked in: Looks-wise I’m still of a mind to stick So it’s all starting to come together, bit pointless on something that started so with the current black in some form or well, at least in my head and it’s made cheap, but with the F-R sharing some another, but maybe satin or something my other project much simpler. design similarities to the NR, the basic cool… carbon… etc. I’m pretty sure I look is enough. Would be nice to have can’t do anything to change the colour/ Basically, I’ve been dithering with the some inverted forks, or maybe the looks of the swingarm, but perhaps a cool GPz and looking at various ways of making rumoured straight-swap for FireStorm/ black for the frame? Hmmm… maybe the bike more modern. So it’s been CBR600FX/Y forks (and the better Nissin that’s all a little too ‘dark’, but making different front-ends, rear-ends, pipes, etc. calipers) but I’ve got new springs, so with the ergonomics a little more sporty with I’ve even been as far as bidding on a full refurbishment for the front and a new rearsets/footpegs and getting the different bits and pieces on eBay and have new YSS rear replacing the MoT-fail rear, clip-ons lower. come close to getting a ZZ-R1100-D it’ll be light-years ahead of where it was rear-end and wheels, but now the VFR is before it was wheeled into a garage for two In the next couple of weeks I’m taking shape in my mind, my feelings are years of solitary… The brakes may need stripping the bike and flogging what I clearer on the GPz. I did enjoy riding the upgrading though, the originals were a bit don’t need: that’s pretty much just the thing as standard (until it conked out on feeble, but overall the original bike was a Venom end can (anyone want it?) and the way home…) so standard it will be. cracking road machine and with new the standard footpegs/footrests and the suspension it should handle well enough. pillion hangers which droop low from This speeds up the process considerably the tail-unit, which will be single-seat. as the wheels, swinger and forks I was Motor-wise and with daft thoughts of I may go for an electronic dash of some going to sell on can now go off for blasting TTS big-bore kits now dismissed as description too… more sport than sports with everything else. And this will be financially daft (and many who’ve had it tourer this VFR. happening very soon, I promise you. done say the gains aren’t that massive) Honest. No, really. cmm instead what I will do is a basic stage-one job of jetting, filter and that lovely GPR exhaust. To be honest, if it’s anywhere near the original 100bhp that’s fine, and if it sounds awesome, all the better. That’ll do… www.classicmechanics.com / 81

workshopwisdom A selection of specialists 82 / classic motorcycle mechanics

for your classic investment workshopwisdom www.classicmechanics.com / 83

Project Ducati 888 racer part 2 WORDS: MARK FORSYTH PHOTOS: DON MORLEY & MARK FORSYTH Twin tales Last month MF set the scene for his rapid racer 888 restoration, so first thing’s first: that marvellous motor. Last month I told you not just someone carrying a torch to bring and knew them all pretty much inside out. about the two-decade me more bad news. Skip forward to last year. Jeff was working pillar-to-post headache out of his mum’s garage while he waited that was my 888 engine Ace Ducati engine man Jeff Green had for the authorities to green stamp his rebuild saga. just sold his G-Tec Ducati servicing immigration papers. Or rather, not rebuilt saga. All I had business and was planning to go and live were boxes of bits, some missing parts and in Melbourne, Oz, where a new job at Spotting a window of opportunity, I still no complete engine. Because the Melbourne Ducati awaited his visa and asked him if he had the time and engine of a Ducati is a partially stressed emigration approval. I’ve been to inclination to tackle a difficult engine member, acting as half the chassis, it’s Melbourne. I can fully understand the project and, foolishly, he agreed. He impossible to even contemplate building appeal. Market Harborough is very nice probably regretted that decision when I an 888 without the engine as everything but Melbourne wins in a town-off fight, rocked up with a van full of minging else hangs off it. It’s where it all has to hands down. I’d known Jeff since the early stacker boxes full of even grubbier begin, right? But, seeing as Ducati only Nineties (or maybe even longer) when he dismantled engine components but built 17 of these bikes and it was such a worked in the workshop at Moto Cinelli, undaunted and armed with a £1500 cash long time ago, the number of people the-then Ducati importer. float to source bits, he set about the job qualified and capable of tackling a and just a month later, I got my engine rebuild like this are not exactly plentiful. The press fleet bikes that came out of back looking like it had just left the factory Or affordable. his workshop in Northampton were in the winter of 1988/89. That, I can tell Last summer I spotted a ray of light in undoubtedly better than they came off the you, is quite a feeling after a twenty-year this depressingly murky situation. And I Bologna production line – a testament to wait. Cheers Jeff. So what did he do to was pretty sure it was a beacon of hope, his factory trained, meticulous approach. turn a sow’s ear into a silk purse? Well, Jeff had also built some pretty rapid 888 here’s how he did it. and 916/926/955 race motors in his time 84 / classic motorcycle mechanics

12 1/ This is the grotty mish-mash of parts that 2/ Starting point. Crankcase halves treated to some loving in the parts washer was dumped on poor, unsuspecting Jeff. before being dried and scrutinized for cracks or damage. Thankfully, bearing in After sorting through the parts he mind these cases are the originals, they passed the Green inspection – deemed discovered, to his joy, that a lot of the items fit to fight another day. “They looked really rough but thankfully cleaned up were for later engines and not relevant or okay,” added Dr Green. suitable for this very early eight-valve motor. A shopping list was made of missing 4 parts and the internet scoured for the 5 missing bits, including parts from America – a rich fishing ground for old Ducati stuff. 3 3/ New main bearing sleeves were pressed into the cases, along with new gearbox 5/ “The scariest bit was the crank,” bearings… 4/ Here, we see the new main bearings being pressed into the new sleeves. said Jeff. “It looked like somebody had already cleaned it up, but I 67 thought I’d check it out just in case, then found it hadn’t been touched at all – probably since new – and was full of crap. The crank was stripped and sludge trap removed to allow the crank oilways to be cleaned out. What came out looked a bit like an oily owl pellet.” 6 & 7/ Here the rods are back on the crank with new big-end shells, this included tolerance checks. www.classicmechanics.com / 85

89 8/ Here’s the rebuilt crankshaft being measured for width to allow the correct preload to be applied to the main bearings. 9/ “It was fairly terrifying to discover the gearbox completely in bits and scattered among several boxes,” said Jeff. “Thankfully most of it was there but all the selector forks and rods had gone walkies. Here are the parts cleaned and inspected and ready for reassembly.” 11 10 11/ Assembled gearbox clusters, crank and rods are here, ready to be shimmed into their new home. 10/ This is an early 851 selector drum, once an easy item to find, now rarer than undamaged Ming vases in bull shops. 12 13 14 12/ Main bearing depth being measured. 13/ Major components assembled into the left-hand case once measured. This allows for a dry-build: gearbox end-float to be double-checked before final build. 14/ Measuring gearbox end float. 86 / classic motorcycle mechanics

15 16 15/ A new timing gear was sourced as the original was missing. The timing gears were a worry as they’re straight cut and match the crank gear. They’re machined as a pair at the factory, also the crank gear acts as a spacer and is different to later models. We got lucky. Or should that be Lucchi? 16/ Some parts were glass bead-blasted to clean off the years of burnt-in clutch dust and heat discolouration. 17 Jeff Green did all this. He knows what he’s doing. 17/ The cylinder heads were cleaned up and inspected. They’d already had some work done to them by persons anonymous but Jeff started from scratch. The boxes of parts I’d given ■ Thanks to Neil at Cornerspeed Ducati him had a massive selection of valves – most of them odd sizes but Jeff found eight to do (01623 238944) for finding me that the job. The top ends were treated to a couple of dry-builds to establish and optimize piston factory kit swingarm shimmed and to head and valve to piston clearances and also to dial in the cams. New belts and bearings torqued to the rear of the crankcases. and some new followers complete the top-end overhaul. 18/ Generator cover, after being alloy welded, filed and sanded and repainted to rectify crash scars. 19/ Taaa-daaa! Just a water gallery union to find and the job’s jobbed. cmm 18 19 www.classicmechanics.com / 87

Bad vibes A few simple precautions can save an awful lot of vibratory hassle, says Scoop. Among the few in four… even apparently vibration free WORDS AND PHOTOS: STEVE COOPER society who saw motors have their issues. A two-stroke vibrations as a good triple should be inherently free of intrusive doesn’t mean the forces are any less thing were The Beach Boys. vibes but watch a Suzuki Kettle’s mirrors potentially destructive. Our opening shot at tickover jump about. shows a case screw on a small stroker twin For classic motorcycle that regularly unscrews itself if the bike is enthusiasts anything approaching Smaller engines have less reciprocating ridden long and hard. The wrong revs at pulsation, shuddering, shaking and the mass so the force or amplitude of the the wrong speed allied to just one slightly like is normally an overtly negative vibration may well be less. However, this loose mounting bolt can repeatedly loosen process. At best it might be a blurred fittings or fracture metal. Where mirror just when you want to know what’s going on behind you and at worst it might 1 be something vital falling off because vibration has caused a fixing to unscrew. 1/ The sheathed electrical cable at the top right should be held under the clip centre but Anyone who has suffered the quixotic vibration persistently liberates it. A discrete zip tie on one of the frame tubes will disrupt the appeal of a ‘Big British Twin’ will know the harmonics going on here and allow the clip to do its job. sensations of numb fingers, fractured brackets and regularly failing bulbs. Such motorcycles with 360º cranks are effectively two smaller singles bolted together. And before I get accused of Brit Bashing the same thing happens to a lesser degree on Yamaha 650s. Place an XS-2 on its stand and blip the throttle hard; it actually leaps backwards several inches as the vibes work their way out of the chassis. When Benelli launched the Sei much capital was made about its lack of vibration with images of a 50p piece sitting on its edge balanced on the filler cap of a running bike. The down side was that a lack of torsional stiffness in the essentially vibration free crank actually led to breakages between rods three and 88 / classic motorcycle mechanics

32 4 5 Fighting fatigue 2/ Delicate instruments require isolating from harmful vibes. Replacing a £5 clock rubber is & loosening… the quick cheap and easy fix. Repairing the old clock or finding a replacement is the expensive solution. 3/ Ignore a hardened damping rubber and be prepared for pain. Two If you thought it was just brackets screws (value 2p) are now on the loose ready to damage the clock face and potential wreck and bulbs that suffered from the tacho. Prevention is better than cure! 4&5/ Batteries don’t take kindly to vibration. Most vibration, think again. It’s quite bikes run damper rubbers at the base of the battery box and often around the battery itself possible to induce metal fatigue in for a very good reason. A few lumps of strategically mounted rubber can save a lot of hassle. key components if vibration isn’t 6/ Rectifiers and regulators don’t take kindly to being shaken. Both hang off the battery box adequately managed. Many a which is mounted on three anti-vibration rubber dampers per side. These little guys will Triumph T120 suffered cracked ensure AC goes to DC and voltages get maintained accurately. front mudguard stays because the Meriden boys only had half the 6 answer. The stays were rubber mounted to the fork lowers so should have been okay but when the bike sat at tick-over the whole front fork assembly resonated back and forth by more than an inch, fracturing the brackets. Yamaha’s equivalent XS650 twin contained more metal in key places so that this didn’t happen. Bar-end weights are a prime example of managing vibration. It’s a given that handlebars will resonate at some point so adding a defined mass which shifts this point away from commonly encountered speeds neatly dodges the issue and avoids white finger syndrome. Nuts, screws and bolts losing their grip is a well-documented phenomenon but one that’s easily prevented. Tightening them up to the correct torque is a sound move, as is fitting vibration resistant washers or nuts with plastic inserts. These techniques all have their place but nothing will work effectively if either male or female thread has been stretched. In cases like these fitting a new bolt to a stretched hole is at best a temporary fix and even re-tapping the thread is unlikely to deliver a permanent fix (sic). In situations like this, a thread insert may be the only option but even then this may not be the perfect solution. If any fitting is loose it needs to be tightened immediately or there’s a real danger the thread may become irreparably worn. Prevention is better than cure: a quick dab of thread locker is the best answer. www.classicmechanics.com / 89

78 7/ Larger metal surfaces can vibrate sympathetically at certain frequencies. Here an oil tank has lost its damping pad but a slice of modern closed cell foam from some computer packing and a spot of silicone adhesive will stop the harmonics from doing any real damage. 8/ Side panels often hang off rubber damping pads but even these can wear over time. Mounting them with adhesive ensures everything stays where it should be. 9 10 9/ The panel’s mounting bracket’s pop rivets have loosened due to vibration. Intervention with a drift and hammer tightens them up and a new bottom damping rubber ensures any buzzing twixt panel and frame will be minimised. 10/ A standard Yamaha barrel (left) versus a pattern one (right). The factory one has sets of cast-in alloy dampers which prevent the trio of longer top fins from resonating. manufacturers believe an engine needs its 11 11/ The fins aren’t continuous in a move to vibes tamed they’ll often rubber mount the reduce sympathetic vibration but this only engine or add balancer shafts. Neither is vibration dampers that decay first. So, works up to a point. Yamaha had to fit fit-and-forget; replacement and/or service keep an eye out for those rubber parts damper rubbers between head and cylinder are mandatory. When lateral motion is that turn a vibrating rattle trap into a fins in a move to damp out profound fin transferred into rotary motion the piston(s) decent classic. cmm ringing causing noise issues AND vibrations and associated laterally moving masses ■ Our thanks to Yambits for parts supplied being transmitted through the chassis. must be stopped and started; this is a for this article. primary root cause of the various pulses distributed across your bike. On the assumption that vibration can never be truly eradicated from a reciprocating piston engine, all we can do is be aware of its causes and effects – taking action wherever possible. Making a working assumption that balancers are adjusted and engine mounts properly tightened we can look at some of the less obvious but easily addressed options for vibration suppression. No engine is entirely free of vibration but the Japanese factories did their utmost to minimise its impact. Footrests, lights, seat bases, mudguards, instruments and numerous other fitments were regularly and automatically fitted with damper rubbers. No-one expected the bikes of the 60s and 70s to be running today yet they are. As ages catches up on the old warhorses it’s inevitable that things will wear out and it’s often the rubber 90 / classic motorcycle mechanics

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The bottom part of the tool is adjusted and placed against the valve head. Project Honda CB125T part 3 Head scratching Ralph is back on with a youngster’s CB125T and in part three he sorts out the cylinder head. Last month the midget the head which pretty much wrote the To start with, I needed to pull all the twin got a new barrel and head off. While technically, I could have valves out of both heads. I used my trusty piston set as part of its tigged some weld in and re-line bored it, Laser valve spring compressor which is a rehab into becoming a decent, a reasonable second hand item seemed neat kit made specifically for bikes. The non-polluting member of our to make more sense. Young Jack, the bottom part of the tool is placed against two-wheeled society. diminutive Honda’s guardian, was the head of the valve in the combustion This month I turn my attention to the charged with searching flea bay and side and the cage part is located at the top cylinder head. The left hand cam bearing soon found one. It was pretty crusty of the valve spring retainer. As the tool is had self-destructed, and the cam had but not as bad as his, so the first task tightened the springs are compressed and dropped and carved an extra groove in was to revitalise it. the split keeper collets can be removed. … and the top part is screwed down against the top of the Using the valve spring compressor to remove the rusty valve valve spring keeper compressing the spring to allow the springs from the ‘new’ head. collets to be removed. 92 / classic motorcycle mechanics

Simple solutions: A bench-set wire-wheel is a must for any workshop. The wire wheel is the easiest way to clean up valves. Something tells me this head was from A couple of minutes on the wire wheel pays dividends. an engine that was burning a bit of oil. properties. To clean the ports and Once the innards of the head were I tend to use a pair of curved forceps, but a combustion chamber I first try and get rid clean, I gave the outer bits a good magnetic pick up tool can also be used to of as much oil as possible with degreaser, degreasing in the parts washer using pick out the keepers. Once the tool has usually brake cleaner. I use a lorra-lorra Jizer which is water miscible, so once been released the valve spring retainer and brake cleaner as it is a very good I’d finished in the parts washer, I could springs can be taken away and the valve degreaser. I buy it in 20 litre tins and wash it clean in the workshop sink. If you pushed out. I make a point of keeping all apply it with a pump-up chemical spray have a decent man-sized compressor it’s the parts together in clearly labelled bottle, which is adjustable to either a fine easiest to dry it with an airline and blow self-seal plastic bags, so all the parts for jet or a spray pattern. gun, always wearing eye protection! I’m each individual valve are kept together. It’s not big into the nanny state bit, but not necessarily essential in this particular When I see the price of aerosols of brake compressed air can be very dangerous if case, but is good workshop practice. cleaner in bike shops it makes me laugh; not used properly. why do punters encourage them by buying Sharpies are best for labelling poly bags it? I find a little wire brush on the Dremel With everything cleaned up, I selected in my experience. Boxes of little poly bags is the best way to get the carbon out of the the best looking valves out of the two sets. cost buttons and make it a piece of cake to ports and the combustion chamber part of Some of them were cream-crackered, but keep all the parts of a stripped bike safe the head. Always let the machine do the we managed to get four serviceable valves until the rebuild, making losses far less work, don’t push it too hard or you’ll without having to buy new. I then likely. Once the valves have been taken out shorten the life of the brush, and the lubricated the valve guides with a very then the stem seals need to be extracted. Dremel’s bearings, and run the risk of light oil and slid the valves in until they There is a special tool available, but if you marking the aluminium. were just open enough for me to be able don’t have one you can probably get them off with a combination of pick tools and Cleaning the ports out with a Dremel with a baby wire wheel. long nose pliers. Never even consider using the old ones again, and the ones that come with gasket sets often aren’t great. If you can get them for your engine, Viton seals are a great improvement and are far less likely to leak. The valves are likely to be pretty scabby and the easiest method I have found for cleaning them is with a wire wheel on a bench grinder. Bench grinders are not big money these days and a wire wheel is so useful for de-rusting fasteners etc. The 8in ones have a lot more balls and are well worth the extra cost. If you can get an old school British grinder so much the better, they have much better torque and can come up cheap sometimes. Always use eye protection when cleaning valves and bear in mind that if they’re from an old bike, some of the white stuff that’s stuck to exhaust valves may well be lead, which is not noted for its health enhancing www.classicmechanics.com / 93

Simple solutions: We think old Ralph likes Wellseal... so get some. Carefully apply tiny dollops of fine grinding paste around the The valve is turned by moving your hands back and forward seating area of the valve head with a small screwdriver. while griping the stick and occasionally lifting. to grip the heads with my fingertips. I then This automagic lapping tool make life loads easier. tried to move the head from side to side to ascertain if there was any wear in the valve guides; luckily for young Jack there wasn’t; he had to have some luck! The next job was to lap in the valves. I dug out the suction cup lapping stick to demonstrate to you how to do the job manumatically. Firstly, the guide was well lubricated and the valve inserted. With a light smear of gob on the suction cup, the stick was attached to the valve head. Using a small screwdriver I wiped little dollops of fine grinding paste around the seating area of the valve head, being extremely vigilant about not getting even the smallest amount anywhere else; it’s not good for bearings! The suction cup must be exactly in the middle of the head or it will come off when you try and turn it. The stick is gripped between your flat hands which are moved backwards and forwards with a light pressure downwards, thereby turning the valve forwards and backwards. When you can feel that it isn’t cutting as well, the stick is lifted a tad and rotated a small amount to move the paste around and then the hand rubbing is continued for a little longer. It is a fairly tedious job, particularly if the sucker isn’t in good condition and keeps coming off. There is a tool available now, that fits in the chuck of a cordless drill, which I use. It isn’t perfect, in that it still uses the infernal rubber sucker, but is massively easier and far less frustrating than the The smaller exhaust valve seat (top) is Apply Wellseal to the mating gasket face of the head. lapped, whereas the inlet is still awaiting treatment. 94 / classic motorcycle mechanics

The forward cam-chain guide is refitted and the mating face Set the left hand piston at TDC and drop the head gasket of the barrels buttered with Wellseal. in place. traditional lapping stick. You grip the body dowels and rubbers needed to be fitted. supply of it to hand in my workshop. I of the tool and slowly run the drill which The new barrel was not quite the same as poked this wire up through the cam-chain cycles the valve back and forth. You still the original, so not all the original rubbers tunnel in the head and gently lowered the give it a lift now and again as per the could be used. The head gasket was then head down over the studs. Once it reaches lapping stick, but it is much easier. Do fed down over the studs into place. I turned the barrels it usually will take a little NOT be tempted to grip the stem of the the crank over until the left hand piston wriggling to get the dowels located and valve with a drill – it’s a bad thing and will was at TDC (Top Dead Centre). This is also sometimes a gentle tap with a hammer or lead to untold misery! Every now and again a good opportunity to determine if the mallet via a block of softwood to get it carefully remove the valve and carefully timing marks on the crank actually tie up fully home. NEVER hit a gasket face wash the grinding paste off with a with the piston itself. With many bikes directly with a hammer; it might seem disposable rag and some brake cleaner these marks can be wholly unreliable, obvious, but I have stripped enough and do the same with the valve face. The though this one was spot on. Kawasaki S2 engines to know that folk do! valve face should be left with a light triples were notorious for having fairly coloured ring as in the photograph with no random timing marks and even the factory And on that cautionary note I must go dark patches, which represent corrosion workshop manual admits as much. downstairs to my workshop and un-break pits. If the seat is badly pitted it might another classic bike that has suffered need to be re-cut, which is outside the In this instant I had a piece of unwarranted cruelty. cmm scope of all but the very best kitted out aluminium TIG welding wire stopping the ■ Next month I’ll be setting up the cams, workshops. The same goes for the valve cam-chain disappearing into the bowels of timing and carbs. head face, though if this is too pitted it the crankcase, as it is soft and pliable, but www.bikerstoolbox.co.uk is easily replaced, assuming availability. stiff enough to be able to be poked through holes; that and there is a ready Once the lapping was finished, I thoroughly cleaned the head ensuring that Poke the piece of wire supporting the cam chain up through the cam chain tunnel of no trace of grinding paste remained. To the head and gently drop the head over the studs. finish off I tend to spray a fine jet of brake cleaner, using a chemical spray bottle, to wash away any last vestiges of grinding paste, followed by a serious jet of compressed air from a blow gun on the airline. Before fitting the new Viton stem seals I refitted the valve spring seats in the bottom of the hole. Often these can’t be fitted when the seals are on the guide. Fitting the stem seals is reasonably easy; just push the seal over guide until you feel it lock into place. I then squirted some engine oil in the guides before refitting the valves. The springs were fitted next and the spring retainer placed on top. The valve spring compressor tool was used again in the same manner as previously and the keeper collets were dropped in with curved nose forceps. Once the collets were safely in place, the compressor tool was gently released and taken off. The front cam-chain guide blade was replaced and I ‘buttered up’ the gasket mating faces of the barrel and the head with Wellseal. While I let the solvents ‘flash off’ for five to ten minutes I checked what www.classicmechanics.com / 95



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Dead Sert! Above: The tackle required to do the job correctly: Top 3/8 drive socket to fit tap and spot face tool; two short inserts If you want a sure-fire way of sorting a knackered thread, and the all-important tap; the spot face tool our Pip reckons he knows the best way. that slides over the tap; two long inserts and Ever had a plug fly out of the final setting tool. a running engine? Not good and positively not conducive to marital harmony if the B8ES happens to catch you in a tender area in its bid for freedom. The fix to this is fairly simple but needs great care at all stages in an effort to keep everything hunky diddly. There are two systems commercially available, the ‘Helicoil’ a stainless steel coil of wire that is wound into a pre-threaded hole by a small tang on the bottom coil, and the ‘Time-Sert’ a system devised in the USA which utilises a ‘solid’ insert as opposed to a coil, it has an external thread which fits a fresh, newly tapped hole and an inside thread to match the spark plug, generally 14mm x 1.25mm but available to fit any other spark plug configuration too. I’m not a lover of Helicoils, I’ve removed hundreds of them and replaced them with First part of the operation: carefully tapping out the remnants of the old thread and Time-Serts. No doubt there are people out forming the new, larger thread for the insert. 98 / classic motorcycle mechanics

Hole tapped and ready for insert. New Time-Sert on a tapered brass bar with a drop of Loctite on the thread, outside only! Right: Spot face tool shown over tap, this arrangement ensures that the new plug seat is exactly perpendicular to the new thread. s the Here we see the finished insert in place. Et voila! t onent it also pr seat for items like thread, I generally give the outside a rub 3-in-1 or similar. This tool screws easily oil g , drain plugs and, of on my wire wheel to get rid of any tiny into the first few threads then appears to cour park plugs. plating deposits (as they come the inserts tighten up as it reaches the last few are flash copper plated to resist corrosion, threads. This is intentional as the last For a standard plug hole repair, first as it’s going into the hole in about five couple of threads are not fully formed and make certain there is no risk of further minutes it’s fine to polish up the outer by screwing in the form tool this process is damage, bearing in mind that there will surface). Now have a trial fit of the insert completed. Additionally the insert is be some swarf created by the tapping into the hole; it should run in very locked into place by this action. process, I don’t subscribe to the notion smoothly. If it doesn’t, examine again for that a plug repair can be performed in any swarf or imperfections. Now a couple It’s probably worth noting that Time- situ. With the head off, screw the tap into of drops of Loctite on the external thread Serts are available in most thread the top of the damaged hole, a bit of of the insert, taking great care not to let configurations, metric and imperial. One paraffin or WD-40 is always helpful here. any get on the inner threads, and screw area in which they excel is in the repair of As the tap starts to bite it’s critically the insert into the tapped hole using a 6mm cam cap threads that have eaten the important that the angle between the tap piece of tapered wooden dowel or in this peach, in this application they are superb and the head is maintained exactly, this case a tapered brass punch, I do this as and can often save an expensive head isn’t easy and you are much more likely to I’ve found it allows me to set the insert in from being binned. succeed if you have a spotter to look out place easily and I can simply rock the for this alignment. Cut the thread punch slightly to free it from the insert A Time-Sert repair is a bit more carefully, backing the tap off by half a once it’s seated. Leave the head for at expensive than having a Helicoil, but let’s turn at frequent intervals, if possible blow least an hour, or overnight if possible and face it, in the scheme of things, on a dark out swarf as you go on, then add paraffin/ then, when the Loctite has done its job night, miles away from home what does an WD. With the hole tapped, leave the tap screw in the setting tool using a drop of odd couple of quid matter? My answer to in place and install the spot face tool anyone looking for a cheap repair in this over the tap, dab of paraffin, then by area is simple: buy cheap, buy twice. cmm carefully turning the face tool you’ll see that it cuts a small depression at the top of the new thread and also a new spot face where the plug will actually seat after the insert is fitted. With the threaded hole scrupulously cleaned with a squirt of brake cleaner, leave it to dry. Then examine the new insert for any imperfection on the external www.classicmechanics.com / 99