woody

He had the ability before, I'd guess a couple of good results have now given him the confidence and consistency he needed. The others must be thoroughly demoralised. Wonder if the know-alls who maintained that the 4RT wasn't competitive in WTC (without having any actual substance behind the opinion) will still argue that point.....

so are we saying here that the PVL sold by Sammy Miller for a C15 is not suitable for trials?

Thanks for this Martin. Both spacers (1) are fitted. I've never noticed that the lock washer (9) should specifically fit one way round so I'll check that too, although it seems to be located ok on the splines. Clutch nut is definitely on the correct way and locates ok. Also wasn't aware that the gear could be installed the wrong way around. I've never removed it but the clutch has definitely been off before I got the bike so I'll check that too. I'll have another go at it on Sunday and let you know. Maybe the pick-axe won't be needed just yet...

Something to be aware of if you do remove the distributor for PVL ignition. The distributor drive shaft also drives the oil pump from its bottom end. When the distributor is removed there is nothing to hold the driveshaft in place (as far as I am aware - there isn't on mine anyway) therefore there is nothing to stop the drive shaft riding up in its housing and disengaging from the oil pump which means the oil pump is no longer driven - not good Mine had a blanking plug which I never gave a second thought to but last time I put the engine back together the driveshaft wouldn't stay located in the oil pump, it kept disengaging when the engine was started as there was nothing to hold it in place. Why this has never happened before I have no idea but I've been very lucky. I refashioned the blanking plug and made it longer so that it rests upon the top of the drive shaft and holds it in place now. Maybe there was/is something missing on my bike to locate the shaft but I can't see anything on parts diagrams. Just something to be aware of. I've heard that some people also use B25 pistons in the C15 as they are flat topped and reduce compression giving a softer bottom end - combined with moving the carb backwards. Not sure if moving the carb back improves torque but it will soften the power delivery by slowing up the gas flow. 22mm Amal will increase response off the bottom end over a 24mm as it increases gas flow due to smaller venturi. So using a 24mm and moving the carb back should provide the best combination for a softer power delivery - in theory anyway... The pre65 brigade in this area reckon that new Amals can come with casting flaws in the airways. Without question, the one I bought had very poor airflow out of the pilot jet housing when an airline was stuck on the pilot inlet at the rear of the carb (with the pilot screw removed and a finger blocking the hole. One of the boys that knows drilled out the pilot screw air passage, tapped out the swarf and when we repeated the airline test there was a much stronger blast of air out of the pilot jet housing. Still however, the bike used to cough stall a lot when opening the throttle (and if anyone else says 'you're trying to ride it like a 2 stroke' I'll swing for them...) unless the pilot screw was right in, or quarter turn out at most. I put the carb in an ultrasonic cleaner last week which should remove any obstruction from the airways and now it will pick up cleanly with the pilot screw just over 1 turn out so maybe there is something in what they are saying about the Amals having flawed casting in some units. I'd also fitted a new PVL too, so it could also be that which made the difference - I'll never know now. I was convinced the PVL that was fitted when I bought the bike was faulty as the swings in performance were to radical to be carburation. When I removed the old one (having bought the replacement already) I found that the earth to the frame from the mounting bracket was not too clever so it could have been that too. However, I cleaned that up, fitted the new PVL, re-fitted my nice clean carb and it runs ok now - should know by now to only change one thing at a time..... I can also recommend the book on C15 by Rupert Ratio (yes, that is the author...) as it has lots of little tips on running and maintaining a C15 - usually find one on ebay but Merlin books have them I think.

Thanks for all the suggestions. I've tried most already but haven't looked to see if the condition of the actuator where the ball bearings are is ok, so I'll check that. Haven't yet tried extending the arm either as I was hoping not to have to do that. Cables and routing are all ok and the lightener arm under the tank is free in its movement. I've also tried a single cable (new) from a 280 but the problem was still there. The actual pull/release action on the cable is smooth enough but it is just too heavy. That's one problem. The other is the mechanical graunching/thrashing noise when engaging the clutch together with the eratic take up. If I ride in 3rd gear slowly with the clutch just around the biting point it's almost as though something somewhere is going in and out of mesh as the drive take up drifts in and out. Sounds and feels horrible. Gearbox is definitely ok as there are no problems at all when the clutch is disengaged, so clutch is definitely the cause of it. Condition of the basket and centre hub all looked good where the plates slide but I'll check them again and make sure and also check again that the adjustment is correct on the actuator. Plates are all new. My other suspicsion is that the clutch gear assembly is worn where it sits on the 2 roller bearings and is rocking/wobbling on the shaft because there are marks on the kickstart gear that sits behind the clutch which indicates that the basket is catching it. The mark isn't constant all around the gear, there are several marks, equidistant around the gear indicating that the basket may be rocking/oscillating to cause that. I wondered if this is what was making the hideous graunching noise when the clutch is used. So I fitted a shim behind the existing spacer that sits behind the clutch hub and this seemed to improve things as it stopped some of the rocking on the shaft as well as moving the basket away from the gear. I've now bought 2 new roller bearings and a sleeve, so I'll fit those, try it with the shim and re-check everything suggested above and see what happens. If I'm not riding it at the Rhayader Miller round Malc, don't ask how I got on, because it will be at the back of the garage with a pick-axe handle sticking out of it....

Question for any of you SWM owners whose bikes have a nice light clutch action - How do you set up the clutch spring tension? Are the pressure plate bolts tightened right up to the end of their travel and left like that or are they then backed off so many turns. Bike in question is a Jumbo which has the lightener under the tank connected up but the clutch action on the lever is very heavy - the pressure plate bolts are screwed all the way in so I'm wondering if they should be backed off a little but as I have no manual or set up info I've no idea. I can experiment obviously but if someone knows how they should be set it would make life easier than trial and error. Although it is a Jumbo I gather the clutch is the same as the disc valve models. If I can at least set the pressure plate pressure correctly it may also cure the other clutch problem which is the snatching, graunching, juddering action that is worse than a TLR and which, along with the heavy action, is making use of the clutch impossible. Any help appreciated thankyou and then I can go and try it out in the next Miller round

The Gripper on ebay is a normal Gripper with a slimmed down alloy tank as I know the previous owner who had it done. Forks are telescos which some Grippers were fitted with instead of marzocchis, so they're a standard Ossa fitment. Same seller also has a MAR which has several 'special features' such as a well engineered exhaust - looks like standard front pipe and middle box with an aftermarket tailpipe from a trail bike or such like, if it has a special system why not show it. Works side panels?? Twin spark ignition - no idea what that is, I'm guessing someone has put a spare plug where the decompressor is fitted so that it has two plugs, unless it really has got one. The head may be special though as it is on back to front.... (ok, joke - it doesn't actually matter on an Ossa as it will go on either way - just looks strange) The bikes actually look very tidy examples and in the case of the Gripper has had an engine rebuild by the previous owner. Just not sure about some of the seller's claims on several of the 'selling points' Getting back to the Gripper tank issues, there are plenty of alloy tank/seperate sidepanel models here in the UK as well as one-piece fibrelass models. I'd guess the parts list only shows the one-piece units as that is how they left the factory and were converted to alloy when they came to the UK. I remember being up at Peter Quinn's place about 15 years ago and seeing quite a few one-piece units hanging up and assumed they were some of the units taken off bikes that were fitted with the alloy versions - wonder where they have all gone now. The tank in the picture in the previous post is definitely a plastic (or whatever) tank and you can see the petrol level through it. For a replacement side panel unit, try Mainly Spanish Motorcycles as he used to have some and may have some left. Use google to find his website/contact details. Or try Wakefield Offroad in the UK 0044 1924 217124 as they have some used parts for the Gripper.

The alloy tank was probably the UK version due to the ban on fibreglass tanks on the road back in early 70s - not sure how long that ban was in force for, maybe even still applies today. Most of the Spanish bikes had a replacement alloy tank although some used a fibreglass cover styled like the original over the top, such as Cota 247. I'm pretty sure though that there are seperate fibreglass tank/seat units too on Grippers as I've seen fibreglass tanks on their own - unless someone has seperated it themselves of course. Whichever the Gripper was fitted with though, one piece or two-piece, the seat fixing should be the same on either. That's a lovely looking Gripper SpudPlark

That's the Saturday trial that starts at 4pm, The Forest Trophy trial is Sunday

Any news on entry list/riding numbers yet? Had a look on the club's website but nothing on there yet but not sure what closing date is/was. Start time in TMX was listed as 4pm... Are there really nearly 200 entries? I thought it was pre-entry only to cap the number of riders after last year

No, sorry Mick, thought I may have one still in situ on a spindle somewhere but no luck. All mine have the flat sprocket conversion fitted

Missed this post originally so only just seen it. Don't know the size of the spacer unfortunately and it's been a long time since I had a bike with a dished sprocket as they just bend the spindles which are made from chocolate, all mine have the flat conversion. May have a wheel somewhere which has the spindle through it and is fitted with a dished sprocket so I'll have a look to see if the spacer is also with it and if so measure it. Could be a few days as it is buried underneath stuff at the back of the garage.

Carlos Casas - Trialero13

If you're fitting a tubeless tyre to a Yam twinshock or mono wheel, make sure you try it out somewhere first before going to a trial with it. Every time I've tried a tubeless on either of these wheels it won't stay on the rim when let down to 5psi. I've had no problem with tubeless on Akront Ossa/Bult rims but never had them stay on the Yam DID rims, they always drop off in one or more places.

Problem is that there could be any number of reasons: - Springs too soft (unlikely given his weight) so that suspension is always sagging meaning it is always riding further down in the harder part of the stroke, which means it will bounce off stutter/braking bumps instead of cushioning them out in the higher part of the stroke. - Springs too hard for his weight, therefore not utilising enough of the shock's travel - same result as above - Springs ok but rear sag setting incorrect - Springs ok but rear sag incorrect and damper settings way off - May have been revalved at some time - Damaged components See what I mean.... Best thing to do is go by the manual. Check that the original springs are fitted - easy if he's owned it from new, not so easy if he hasn't but most rear springs have the weight/rating on them somewhere. Not sure about the fronts but assume they are original. Then return suspension to standard compression/rebound settings and set the rear sag using spring pre-load. Normally static sag is about 30mm and sag with rider on board is 95mm. When rear sag set, sit in the middle of the bike and bounce it up and down, front and rear should move equally. Then try it again and see if there's a difference. The EC Gassers are normally credited with plush suspension and shouldn't need tweaking for a 10 stone rider. If it's only an 05 bike the suspension, if unmolested, should still behave as new. If standard settings don't improve things he could send suspension to one of the suspension specialists (WHO UNDERSTAND WHAT ENDURO IS...) and explain what is happening and they should be able to set it up to suit his weight/riding style. I've had a couple of KTM rear shocks done by KAIS and been pleased with the result, they understand what is needed for enduro. KTM suspension is generally too hard from the factory, it's ok on faster stuff but too harsh on slower going in woods, over roots etc. The bike used to clatter off roots instead of ride over them. After it was done (softening the valving in the second half of the stroke, fitting stronger spring) it behaved as I expected it to from the factory - ie; like an enduro bike, not a mx bike set up for sand tracks...

would you believe there is one on ebay...... ebay

If it was suggested it's running rich it could be too rich in oil or the carb could be letting too much fuel through - or both. Either would cause uneven running and excessive smoke. Oil - 75cc is a bit lean on oil for an old steel liner engine, even on modern synthentic, so that rules out too rich in oil. I'd suggest 100cc per 5 litres though which is 50:1. Castrol TTS is good and doesn't gum up rings and silencers. Carb - if standard jets are fitted, could be the float height set incorrectly letting too much fuel through. It's something that is difficult to answer without seeing the bike running or knowing why people thought it was rich. Did they just mean it was lumpy off idle, in which case it is more likely to be just carb adjustment. It could also be a gunged up silencer which can also give the same symptons as a bike running rich. First check to do though is the carb, make sure jets are correct, none loose, needle position correct and float height correct. If so, then a restricted exhaust could be a possibility. What they used to do on those is cut the rear silencer open, rip out all the wire wool 'packing' and then drill a hole in the end so the exhaust gas goes straight out, rather than exit through the holes underneath. No idea if this is worthwhile mod or not as never tried a 'before and after' bike but I'm told by someone who's done it that it makes them go better. If the middle silencer is gunged up you can cut it open and re-pack it. It's is a pig of a job but worthwhile if it's needed.

Sammy Miller sells them or you can make your own by knocking the centre out of an old spark plug, screw it in the head, find TDC, slide a pencil down it and mark TDC on the pencil level with the top of the plug. Take out pencil, put a mark where the timing should be above the mark you made for TDC (eg 2mm above if your timing should be 2mm BTDC) and you have a home-made timing tool. When the piston is pushing the pencil up through the plug, when the timing mark appears you are 2mm BTDC. Tool is obviously better though.

Loved Elias' pass on Rossi, even more so when he ran him wide in the corner. Loved it more so to hear Rossi's toys coming out of the pram and bitching afterwards about Elias' riding in a dangerous manner - rich coming from someone who isn't adverse to punting people out of the way or using them as berms, never so more blatantly than Gibernau at Jerez

And therein lies the problem. It's supposed to be a classic series with no-stop sections. Making them tight just encourages trick riding - against the rules but it is what happens when sections are too tight and riders aren't given a 5 for it. What's the bloody point in having a classic series with trick riding. That's what modern trials are for. I had enough of seeing that at the last round which is why I didn't bother entering this one. I know it gives the organisers problems, but I think the trial was much better when it was held in February and peeing down with rain or snow. Sections didn't need to be tight and the big climbs were a real challenge in the wet. Unfortunately I think the Classic series is losing its way and its sight of the original concept.

Greeves, is that the full model number of the Dellorto? Also, is it a type that is fitted to current bikes such as GasGas, Sherco etc. What size is it?

Sounds like you have a MK1 or 2 247 Cota with the 'bulges' either side of the fuel tank. Parts can be a bit hard to get in the UK, most likely sources are Miller, Mainly Spanish, Gordon Farley. Sandifords don't seem to have much at all for the older bikes. Bultaco UK are starting to cater for other makes but doubt he has much for an old Cota just yet. iN THE usa, Jeff Nolen in Texas specialises in Monts and has just bought up old stock from Sandifords. Can't remember the name he trades under, Vintage something or other but someone from the US should know. Also Southwest Montesa in the US. You should find it a nice handling bike but as I remember, they could be a bit slow/gaspy off the throttle, the later MK3 and 4 were more responsive. Don't know how it would compare to a TY250 though as never ridden one, only Majesty. Should be a 5 speed I think.

You should be able to make a flywheel puller fairly easily. From memory, assuming yours is the purple wheeled model, you need a strong plate of metal (ie, one that won't bend under strain) drill a centre hole and tap a thread in it to take a bolt which will screw up against the crankshaft. Ideally, taper the end of it so it doesn't damage the crankshaft thread. Drill 3 8mm in a triangle around the centre hole to match the three holes with 8mm threads that are in the flywheel. Put three equal length 8mm bolts trhough the holes and screw them into the flywheel. Be very careful not to screw them too far into the flywheel as if they protrude through the other side they will wreck the coil windings if you turn the flywheel. Screw the centre bolt through the centre hole and keep on until it touches the end of the crank. Keep on tightening and the metal plate will be pulled backwards away from the flywheel until it comes up against the bolt heads. Keep on tightening the centre bolt and it should pull off the flywheel. It helps to keep tapping the flywheel with a hide or copper mallet when it is under tension to shock it free as if it has never been off it will be very tight. You'll have to work out lengths of bolts etc. The centre bolt needs to be longer than the other 3 and needs to be a strong enough thread that it won't strip, so 10 - 12mm? and the plate should be 8mm thich as a minimum? Similarly, the 8mm bolts need to be screwed into the flywheel far enough that they won't pull out of the threads under load, but not too far in for the reason above. This is from memory as it was a long time ago that I made one for mine and have no idea where it is now, but it should give you the idea of what to do. If you are going to buy one, there were 3 different flywheels fitted during the production run of the TYZ and they all take different pullers, so make sure you give the dealer the engine number so you get the right one.

If it is the original carb and the bike has had a lot of use in its 30 odd year old life then the chances are the carb body is worn, as well as the slide and letting air past the slide. This is only noticeable on very small throttle openings, when air leaks around each side of the slide, weakening the mixture and can give symptoms similar to those you are describing. When on half throttle and above the slide is open far enough that it is pretty well clear of the venturi and therefore the effect of the worn body/slide isn't noticeable. It is also common for the engine to not shut off cleanly when the throttle is closed as the air leaking past the slide will draw fuel and make it run on a bit until it dies. If the body is worn you'll waste your money putting in a new slide as it will still let air through. If you are serious about using the bike, buy a new Amal. You can no longer get an original type 627 27mm version but the 626 26mm will work just as well. You can pee around for ever with the old carb and you may always be compensating for some wear somewhere when trying to adjust it. It could even have had the flange overtightened at some time which may have distorted it, another place where air can get drawn in - check it against a flat surface. If you replace the carb, I'd replace the plastic heat shield/gasket it bolts up against too. Jetting should be no problem if you buy the carb from Miller as they will know the sizes. Not sure if bultaco UK stock the MK1 amal. You could also go for the MK1 version which has a choke lever instead of a tickler. That's the only difference, same carb apart from that. From memory, I think jetting is 25 pilot, 106 needle, 160 main, 3.5 slide. Amal MK1 needles are all the same (2 stroke that is), there is only one type - set on middle notch.

I'd probably wait and see how the bike runs on the Amal first before moving to try another carb. As far as I understand it, the 340 does have a softer power delivery than the earlier 325 bikes. I have tried both Nick Shields and David Braithwaite's 340s recently and both have soft delivery, one has a Mikuni, the other the Bing. One was a tad cleaner off the bottom but may be due to set up rather than carb type. Personally, I wouldn't entertain the idea of a used Bing as it may be worn out but how do you tell. If it is and you don't know you could spend an age trying to get it to run right thinking the set up isn't right when it never actually will as it is worn out. If it runs too soft on the Amal there are other ways to quicken the power delivery. Get a second hand clutch weight and skim some weight off it (no idea how much though) and fit a 250 ignition flywheel (they're lighter) which will enable the motor to pick up quicker. Both should be available cheaply and it is something that isn't permanent if it's not what you want, just refit the originals. Re-packing the exhaust can also make a difference to the motor's performance and smoothness. I once split and repacked the middle and rear silencers on a 325 slimline and that motor, which is completely standard is still so smooth and torquey to this day. A pig of a job but worth it in view of the way it goes.