21 minute read
Workshop rebuilds
Thanks to pixelation I’ve got the bracket and the bolts wrong on this bit.
A bit of a puzzle
For some reason both major restorations in the workshop are the source of bewildering puzzlement as they refuse to play nice.
Words and pics: Tim Britton Media Ltd
Rebuilding a motorcycle is easy. You buy bits and fit them together, once all the bits are in one bit, fill it with oil and petrol then go ride it, ‘simples’ as the annoying/cute – depending on your viewpoint – furry critter on the telly would say. The task is made even easier by long production runs of basic models in the British industry which mean a high degree of interchangeability in the parts department and the habit of the Japanese industry to ascribe a part number to every conceivable bit and provide schematics of where they should go… In the case of the latter I know what I would like to do with these schematic drawings as it is clear their producer has never had to use them to identify parts during a rebuild.
This looks more like an MX exhaust.
Quite a bit of welding has gone on here, maybe this is the problem.
First job was to go over the bike to remind myself what had been done as thanks to Covid causing mayhem at the engineering place where it was in for welding it’s been away for a while. I haven’t been idle though and a chance contact at an open day when NE Vinduro lad Gav launched his Glendale Classic Dirt Bikes business we now have an original head steady which was pretty much out of stock anywhere.
The fasteners to hold it in place are available and came in the box of bits with what seemed like hundreds of parts which go into fitting up the exhaust system. We have two types of exhaust and a brand new front section and the intent is to make one tip-top exhaust from the better of the two systems and have the new
Lots of new bits to make things easy. front section welded on to the better pipe. It’s no great revelation to say the way the front pipe sits makes it vulnerable to damage… the shocking revelation would be to find it was undamaged. So amid the hustle and bustle of real life a quiet hour or two was set aside to offer up all the bits of tube and new bracketry in the hope it would all fit in place with the minimum of fuss. One fine day such a scenario will happen in the world of rebuilding old motorcycles and will likely coincide with pink fluffy bunnies fetching cups of coffee and handing me parts from a magic box… in short nothing actually fits in place, if I put the front pipe on then the rear muffler – Yamaha’s word not mine – won’t fit. As the muffler is pretty much a sound bit of kit and undamaged in any way, shape or form I’m not going to alter this bit especially as it lines up with all of the bolt holes in the frame and sits nicely when the front section is on the work bench rather than the bike. The schematic drawing from Yamaha’s
The exhaust seam has melted part of the petrol tank.
microfiche shows broadly I have all of the bits but it is blown up so much the pixelation makes it useful as only a guide. As far as bracketry is concerned there is only one correct way for them to fit but at least three wrong ways and thanks to the pixelation the only thing I can be certain of is I have the bracket on the correct side of the motorcycle.
We explained what had happened to create these problems in the last issue and the ‘465itus’ is a known term. The damage is apparently always on the exhaust side and with pipes being from thin steel they suffer the damage at the back end mainly.
No matter what I did to the pipe-puzzle I have, it wouldn’t line up at all and eventually I felt there must be something else amiss. On the shelf in the cupboard are two petrol – gas – tanks, one being originally white, the other a nice blue colour and the one we’re eventually going to use. The IT came with the white tank and I went and had a closer look at it… on the underside where the exhaust goes there should be some clearance; most people will understand a hot exhaust pipe shouldn’t be going too near a plastic container filled with petrol. There was no clearance at all, worse the seam at the top of the pipe had melted into the tank. Further inspection of both the exhaust front sections showed the one it came with has been welded where the vibration isolation damper connects the pipe to the frame… I mean seriously welded as in huge sections of it. This suggests a less than perfect repair job somewhere in its life. Our new section of front pipe is a well made bit of work and I feel the Yamaha original would have been equally well constructed – however the mess which is in place has several bits of steel stuck together to form an approximation of the curve.
The reason for things not lining up in the pipe department started to become clear, or clearer at least so there will have to be some cutting and welding going on. But at first I’ll want to be sure this pipe is in the right place; the advantage I have is at the moment it is no good at all and whatever I do can’t make it worse. What I do need to do though is take another look at an IT465 which is in one bit and unmolested but this time with an idea of what I need to know.
…the replacement section is well made but the exhaust pipe needs a lot of attention before it is welded on.
Great things – like noise – were hoped for…
Tales of Triumph…
… or adversity triumphing over success. Ever heard of someone snatch failure from the jaws of success? Yes, it’s one of those jumbledup misquotations which aptly describe some form of sporting disaster which happens when all of the elements for success still manifest in failure at the last minute. I know exactly how such unfortunates feel. Once I’d given up trying to make the engine run with the distributor and decided the appearance briefly of a spark at either plug to be a success and moved on to an electronic kit from Boyer, I was sure things would work out a lot easier. A cam was changed to drive the rotor magnet, a cobbledup timing case with a points housing was fitted in place and all seemed well. Turning the engine over with my size 11s brought a healthy spark to each plug and all was going well. A bit of petrol in the slave tank, some oil in the oil tank and gearbox and all was deemed good to try. With a twin it is possible to have the ignition 180 degrees out, it’s no great hardship to swap the plug leads over though and for just this reason the leads were left a bit long. I’m sure you will appreciate it is easier to shorten a plug lead than to lengthen it… though I have done this in the past – on a Montesa 200 in case you wondered. So, carb flooded, bike in position to kick without the kicker ending in a heap on the floor and several vigorous kicks resulted in not a pop, bang or feeble splutter.
Swapping the plug leads over produced equally no effect.
The tapered washer holds the rotor concentric to the crank… an idea from Royce Creasey in the old days.
As there are 360 degrees in a circle there are potentially 360 degrees where a spark could occur on each cylinder. However there are only a few of these degrees where the spark should occur and all of them are before top dead centre – BTDC. For a Triumph twin there are several ignition settings suggested, the low power 3TA has less advance than, say, the sporting T90 but there should at least be a semblance of running, maybe a pop or a bang if not a healthy brrmm! The problem is that measuring the ignition timing isn’t quite straightforward when combining bits from several models. I agree it shouldn’t be difficult but when advance ranges in both metric and imperial linear measurements as well as degrees are offered things become slightly more complex, at least for me.
The only answer was to start slowly and work through the setting-up procedure to eliminate problems. I did wonder if the alternator perhaps wasn’t producing a strong enough current and set to and swapped the thing which isn’t easy given the way the wire is routed through the most inaccessible parts of the engine. To this end I laid the wire over the top of the engine until the happy day when the engine makes a noise and it can have the neatness wand waved at it.
With a replacement alternator on and a spark running again to the plugs, the next stage was to check the cam timing with the degree disc on the crank and the tappet settings at 20thou clearance. This is not easy to achieve either as there seems to be not enough room in the rockerbox for my fingers, two spanners and a feeler gauge. If there is an easy way to determine this setting please let me know and even Triumph acknowledged how difficult it was as later rockerboxes have an access plug in the side so a feeler gauge can be slid in.
Triumph do provide helpful marks on the cam wheels to make cam timing easy but a check of the settings is worthwhile and they do match what the maker says. Resetting the clearances to the two and four thou operating dimensions and the suck, squeeze, bang, blow settings of the engine should be correct. The ignition timing is set to what the ignition kit makers suggest and still there is no sign of life, which is exasperating. The only thing left to check now is the actual compression; it seemed okay on the initial build but even for a mild 350 twin there should be a little more resistance to the kick-starter action. Such things are fun to deal with, aren’t they?
I have a selection of alternators.
It should work but doesn’t… more investigation.
Almost ready for the off, Sealey loaned us a slave tank but we didn’t use it in the end.
Fuel for thought
A topic of much discussion in the classic world is the modern equivalent of petrol…
Words and pics: Tim Britton Media Ltd
The effect on performance of our older motorcycles forced to use modern fuel is a major topic of conversation in our scene. Comments such as ‘petrol ain’t what it was…’ and more graphically ‘this modern crap’s useless’ are common. There are,
CLASSIC FUEL SOLUTIONS
The company is based in Stockport and has distributors at various points around the country. Contact Classic Fuel Solutions on its website www.classicfuelsolutions.co.uk for information. See the team at Telford or check where they’re going to be at events. The fuel has a long shelf life unlike modern ethanol stuff which seems to go off as you pour it in the tank.
as ever, alternatives to pump fuel and racers have long used AvGas but as most engines on piston-engined aircraft rarely rev beyond 4000rpm so the fuel needed for them is developed to suit this rev range. Even trials bikes rev higher.
A couple of issues ago we featured a new-to-us classic fuel from Classic Fuel Solutions. It is 105 octane rated – five star if you’re my age and can remember it – leaded fuel for older competition vehicles and seems to solve the problems we as a sport are having with modern petrol. So, we thought ‘let’s give it a go’ and poured a tankful into a bike and rode a few sections.
Our test bike was a well-developed TLR200 which has been ridden in the Rockshocks-backed trials series and performed well on fuel designed for garden machinery and small engines.
The bike is well set up, has a TY Offroad ignition system and runs a Mikuni flat slide carburettor from Allens Performance Ltd. All we did on the day was to drain the old fuel and replace it with Classic Fuel Solutions’ Formula 105.
Chatting to our test rider Dave Hull and having heard similar comments from other people there are issues with bikes popping and banging on the overrun and running out of steam on hill climbs. There are also take-off hesitations when a rider is trickling up a stream and needs to crack the throttle open to help lift the front wheel. Once filled up, Dave set off down to the sections and told me he felt the exact point when the old fuel was used and the Formula 105 was being sucked in. “What a difference!” he exclaimed. The transition point was as he dropped down the fellside and opened the throttle to go up the bank on the other side – the bike pulled away strongly. He gave it a more vicious test by powering up a steeper hill and making the engine slog in a higher gear. With other fuel he has used this would have bogged the engine down but not in this case. Dropping down the hill with the throttle closed there was no popping and banging in the exhaust.
Next test was a tricky stream section used in our club’s Baa Classic which was as slippery as a slippery thing. Using throttle control to guide the bike there was an initial look of surprise on Dave’s face as a hesitation he was expecting didn’t happen… I promised I wouldn’t use the pic though. He was ready for the next try and the bike responded well to the throttle. We could go on and talk about burn rates but I don’t know them, or discuss evaporation and atomisation but again I don’t know them.
What I do know is Dave, a typical club rider, was impressed and felt the difference from one fuel to another.
Above: No running out of puff on the incline.
Top right: Our man found performance in the slippery stream to be confidence inspiring.
Bottom left: “Just make it gasp for us Dave… then power away.”
THE SAFET Y THING
I can’t believe I should be writing this but it seems stupidity in the wider world is thriving and all sorts of things are passed off as “well, no one said not to…” and when a packet of salted peanuts has to have a warning ‘may contain nuts’ on it… I’m sure everyone in motorcycle sport will know not to drink petrol, or wash your face with it, or smoke anywhere near it as they will understand bad things will happen. It should be stored in a sealed container, kept away from children and sources of heat. If you have a can of petrol then you should have a dry powder or foam fire extinguisher too, check it is rated for petrol fires and stay safe.
YES AND NO...
Yes it works in two- and four-strokes Yes two-stroke oil will mix with it Yes it works in autolube systems No it won‘t go off overnight No it’s not compatible with catalytic converter and lambda sensor systems No it won’t rot your glass fibre tanks
DIRTPRODUCTS
This is where the world of dirt bike suppliers tell us about what they’ve got going on which will make your bike a bit better, your appearance a bit sharper and your track cred… well, two out of three ain’t bad to quote the legend who was Meatloaf. Want to be in here? Contact editor Tim Britton cdbeditor@mortons.co.uk or advertising exec Leon Currie lcurrie@mortons.co.uk 01507 529465
1. Brain Pal
No doubt about it – motorcycle headwear has changed considerably since the early days and ReactiveParts.com told us its 6D’s ODS technology is an award-winning energy management system which reduces energy transfer to the brain during impacts. This makes the ATR-2, dubbed ‘Next Level Brain Protection‘, the safest MX helmet in the world, says the team at ReactiveParts.com, and that it’s the nicest fitting, best balanced, most luxurious MX lid on the market. And look what you get with it… a sleek helmet carry case, with pockets and extra room for carrying your gloves and visors to the track. Every helmet comes with an accessory pouch with spare screws too!
Award-winning research. Award-winning materials. A no-brainer!
Available in youth and adult sizes.
The nitty gritty What is it? It is a top line MX helmet What’s the cost? £224.99 online Where d’you get it? Go to www.ReactiveParts.com
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2. Fabulous forks
REH Forks Ltd has added a new product to its range of classic trials forks, yokes and bolt-on options. Called VRS System - Variable Rate Spring System – it has been in development for 18 months and has Patent Pending status.
Far more sophisticated and with much greater performance than a ‘dual rate spring’, VRS System is made up of 12 components including anodised spacers, a push rod with three options depending on the fork leg length and a compression spring counter-wound against the REH mainspring to prevent binding.
The VRS System spring combines with the mainspring by engaging deeper into travel for the bigger rocks, drop offs and long descents where the front brake is heavily used. With a two-spring system in play, the engagement of the secondary (VRS) spring can be adjusted so it takes effect earlier or later depending on rider preference without compromising the initial, supple travel of the forks.
Further adjustment can be made by fitting VRS System to one or both fork legs.
Another major benefit is that the fork sits higher in the travel, making the steering more consistent and the bike more balanced.
“It improves the feel of the bike, increases confidence and reduces physical effort,” says Duncan Macdonald of REH Forks. VRS System can be retrofitted to all REH Forks sold since the brand was relaunched in 2014. It is not compatible with any other forks.
The nitty gritty What is it? Variable Rate Spring System for REH forks What’s the cost? It is £60 plus VAT Where d’you get it? www.rehforks.com or call 01751 417371
3. Top yoke
Steering feeling a bit off, yokes looking a bit tired? Or perhaps you want to take advantage of a bit of an update. Audit CNC Solutions has introduced this top yoke to its range. Made from aircraft alloy and CNC machined before polishing to a high finish the yokes will be a touch lighter than standard and come with a choice of handlebar clamps for either fatbars or standard diameter ‘bars. All fasteners are high quality stainless steel so the yoke will remain looking good.
The nitty gritty What is it? A new top yoke for a TY250 Mono Yamaha What’s the cost? £120 plus VAT and postage Where d’you get it? Call Ossy Byers at Audit CNC on 07818 056207
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5. Magnificent mono
Monoshock suspension units are tucked away in the middle of a motorcycle where they take all the pounding which comes the way of a dirt bike. Best will in the world they don’t always receive the servicing attention they should as there often needs to be a bit of stripping down to get at them and ‘I’ll do it next time’ or ‘it was a dry trial’ can pop up in the conversation. Like any other suspension unit though they do go up and down an awful lot of times through a typical event. Once the internals are past their best then the time comes for replacement. Rockshocks tell us they’ve supplied a variation of these units for bikes as varied as a TY250 Mono and a Honda XR200R to name two more common machines and a Mecatecno Skywalker to say a less common model. It is likely they could do something for your mono too.
The nitty gritty What is it? Rockshocks rebuildable monoshock unit What’s the cost? Depends on application, specification and colour Where d’you get it? From Rockshocks www.rockshocks.co.uk Tel: 01234 741800
4. Pick a colour…
What colour would you order your Rockshocks suspension units to be coated in? Are you a conservative traditionalist who feels black served the suspension world well for decades and anything else is dangerously modern or would you, like a Rockshocks customer did recently, order these ‘in your face’ purple ones? Or one of the other colours offered by Rockshocks such as blue, gold, green, red and yes, black. There is of course no reason to stick with just these colours either as Rockshocks HQ advise us there are other colours available too on request so perhaps your favourite colour is in its options range too. Rockshocks are fully rebuildable and serviceable, tailored to a rider’s needs; the company's website has lots of useful information and a helpful tech film too.
The nitty gritty What are they? Rockshocks rebuildable rear suspension units What’s the cost? Depends on application, specification and colour Where d’you get ‘em? From Rockshocks www.rockshocks.co.uk Tel: 01234 741800
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6. Let’s not twist again
Billet alloy fork yokes are the in thing these days – using aircraft alloy and CNC machining all manner of special machines can be accommodated. Take these yokes here for instance; a special request for a Wasp frame and effectively a one-off set, they’re pictured here waiting for the frame to arrive so the spindle can be produced at the correct length for the steering head. So if you’re on with something and need a set of special yokes for your project then perhaps Audit CNC Solutions could be the place to go to. As ever with special requests you’ll need as much information as you can, the lads are good but not mind readers.
The nitty gritty What are they? A set of special yokes for a Wasp frame What’s the cost? Impossible to say for specials, call them and ask Where d’you get them? Call Ossy Byers at Audit CNC on 07818 056207
