woody

Axul - you can change Falcons damping too, just a bit more fiddly and you need a mountain bike shock pump to pressurise them again. Generally though, you don't need to mess with the Falcon damping as it's usually fine.

Not sure what you were told by "have to get the conrod kit to get the bearings". The conrod has the big end bearing on the crankshaft, so if that is worn then yes you buy a complete new conrod kit as a replacement. It's an engineering job to fit it into the crank. The other bearings are main bearings and nothing to do with the conrod. They can be replaced independently of the big end bearing, although given the relative cheapness of main bearings, it's prudent to replace them as a matter of course when an engine is reassembled. Pricing a bike in that state is difficult but most bikes have a 'base' price regardless of condition and that base price seems to be around £400 - £500. The 349 isn't the most popular of bikes, unless it is one of the last models which differed considerably from the first red models and the next white one. There is a nut and bolt rebuild 349 for sale at the moment for £1250. I think you'd do very well to see anything like £750 and would have thought closer to £500 - odd. Fact is, if you do a thorough rebuild on a twinshock, you'll spend more than the bike is worth in terms of sale price, nine times out of ten, so never look to rebuild one with a view to making a few quid on it. It rarely happens.

I'm also pretty sure that if you fit it with the flat side in, the chain will rub on the crankcase (or can, depending on make of chain) As Steve says, it's not just the tab washer that is a problem with the 10 tooth sprocket, the chain can also catch the nut as well, again, maybe dependent upon the make of chain. I think the original nuts were also shouldered with a boss that kept them away from the chain. Those you buy now are flat, hence the problem. You can always space the nut out from the sprocket. Clean the threads on shaft and nut thoroughly and loctite the nut on. Shouldn't need the tab washer.

You're going to get a mix of answers that will tell you nothing as everyone's opinion is subjective. Opinions will vary as some riders give their shocks a much harder workout in harder trials than others who ride easier trials. Consequently the behaviour of the same pair of shocks in those two extremes would differ. I'd say Falcons every time. What matters is what you think. Ordinarily this question comes up when someone is thinking of buying a pair of shocks. You already have both sets in your possession, the only way you're going to know for sure is go out on the bike and try them both over a varied selection of sections.

MM definitely got bundles of talent but I don't think he's going to have it easy by any means. Testing and practise and even qualifying times don't always give an indication for what the actual races will bring. There was nothing between Pedrosa and MM yesterday and Lorenzo closed the gap right up in the actual race from a second a lap down over the rest of the weekend. And Crutchlow..... what a boy. Interesting times ahead...

I haven't heard of rod kits being a problem to obtain before. Pistons yes, they're hard to get for the 349 but fortunately you have one of those already. Rod kits shouldn't be a problem, unless the situation has changed recently. Have you tried here http://www.inmotiontrials.com/product-category/engine-parts-montesa/page/2/

If the shaft was bent and causing a problem, the shafts movement throughout the entire range would most likely be affected, not just prevent 4th and 5th engagement. Easy enough to tell if the shaft is bent by removing the clutch cover and seeing how easy it is to withdraw it over the shaft. If it's bent it will most likely come out with the cover, rather than stay in situ with the cover sliding easily off it. Once you've checked the shaft, remove the selector pawl assembly that the selector shaft engages with (three screws) and check that the two pawls haven't got chipped or broken edges which will stop them engaging properly in the selector drum. Unlikely as again, this would affect movement throughout the entire range, not just 4th and 5th gears. Once you've done that, there is nothing left to check really that isn't inside the gearbox. Maybe if someone has assembled the engine clumsily when joining the cases, the selector drum housing could have picked up and made it stiff, but again you'd expect that to present itself in all gears. As it's had a rebuild it does seem the most likely cause may be the selector fitted incorrectly, which means a strip down to correct the fault. I'm sure the Haynes manual may even refer to this but been a long time since I looked in one. The selector fork in question has bosses either side where the shaft runs through. One is larger than the other. If the fork is the wrong way around, it can't slide far enough to engage 4th gear. The last time I experienced this was in 1977 on a mate's Pursang that he rebuilt and got the selector wrong, so it's stretching my memory a bit... We took it out to try it after the rebuild and only 3 gears.

It's possible to assemble the gearbox with one of the selectors upside down, or wrong way around, forget which. If this happens then you get no 4th or 5th gear, only 1, 2, 3. So if the engine has been rebuilt this is a possible cause. If this has happened since you've been using the bike with all gears working, then you could have a broken or bent selector. As per the question above, when did it happen, after a rebuild or during use.

Generally smooth motors, but some Sherpas can make some strange noises when you drop the revs right down to nothing and ride at near stall speed, nothing untoward but possibly the grating noise you describe. I've heard it even on a fully rebuilt motor. No idea what it is but it's only at that point where the engine is almost stalling. There could be other causes, ignition flywheel catching the inside of the timing case if it has previously been damaged by the chain coming off. Clutch crankshaft weight loose, even the mesh between the bottom frame tubes touching the engine through being dented from rocks can cause vibration noises you may think come from the engine - same for the alloy bashplate on the later bikes. If it's anything more than that then you're going to have to look at the possibility you may have the onset of main bearing wear, or just a worn piston that is noisy but doesn't cause any loss in performance.

If it's a new frame kit you mean, contact Jim Pickering who makes the Drayton frames. There are a number of satisfied customers with these now. 07850836571

Yes, 1 down 4 up. The older Sherpas aren't very quick on the road Gearbox = 600cc Clutch = 300cc - if you have the original steel plates, use ATF

Short memory TL - last year. Pedrosa Lorenzo, Brno.

It doesn't look too bad to be honest, I bent one worse than that on the left hand side and it caused the shaft to bind in the casing, so it did affect gear changes. Nothing damaged inside though and I'd guess you'd really have to hammer it one to do so. If it is changing gear ok and the oil seal isn't damaged and not leaking oil then you won't hurt riding it a bit longer. Eventually though, it may prematurely wear the oil seal on the shaft. You can get them from ebay from time time but you're reliant upon the description being good - ie: not bent and with good splines. Better off to try Bultaco UK, Sammy Miller or John Collins (JC Motorcycles Port Talbot) to see if they have a good used one. They'll know if it is good or not. Bultacos by the way are one of the more straightforward engines to work on.

Rossi rode well, no denying it, but yes, the Eurosport duo went way over the top. All of a sudden, we're back to the days when a myth was created, only one rider knows how to overtake, only one rider can ride on worn tyres etc etc. Gets a little irritating pretty quickly. If another rider had made the mistake he made at the begining which nearly took him out and another one, maybe two riders, there'd have been criticism for sure, but for him, it's an acceptable risk. Double standards. Fact is there are only four full factory bikes, so 4th should be his worst finish, he shouldn't have a satellite bike in front of him. Cal was unbelievable but where he had the speed advantage over the Hondas around the back of the circuit, he couldn't use it as two Hondas were in the way. Maybe his bike just didn't have enough go to get up the inside of them, maybe he just couldn't do it, who knows. He must have been gutted when Rossi breezed past him up the straight. Something tells me he's not going to get any upgrades as they will not want him harrassing the factory duo, although I daresay Lorenzo had something in reserve, just in case.

Only you know if it's affecting gear selection as you're the one changing gear.... However, if you need to change it, it's an easy job and only needs the clutch cover removing, the shaft can be removed without removing anything else. You may have to cut the splined part off the shaft to draw it through the hole in the casing though, if the shaft is too bent..

Who care's ? He does, it will probably needle him forever that he couldn't ride it, particularly so given the results his hated rival got on it. He and Jerry Burgess accused Stoner of not getting the best out of it due to lack of set up knowledge and not trying hard enough and attributing the crashes to pushing too hard too soon in a race. They said rider error, not the bike. Ooops. Dovi's gone well on it tonight.

Yes, it's much easier to do it properly with the cases split. I've never tried to replace the spring with the engine assembled but you may as well have a go now the old spring is off... Only way I can think I'd try it is locate the spring into the shaft and then get a long / thin nose pair of mole grips and attach them to the spring just below the 'hook' part that locates on the stud with the lock nut. Then with the spring firmly held in the grips try and wind it round the shaft and locate the hook on the stud. That's how you have to do an Ossa kickstart spring. Not sure whether you'd have to go around the shaft once or twice to get the right tension but I guess you're going to have fun finding out...

Is the engine assembled or are you rebuilding it?

Patrick, I can't argue with your physics as I have no qualifications in that subject. I can only speak from experience. The 300 Fantic I tried with specifically designed large volume airbox to boost performance was no better than a standard bike. When I've run my Ossa with no airbox, just a piece of gauze across the carb intake, there was no difference in performance and you can't get a better airflow than straight into the carburettor with no airbox in the way? The engine can only draw as much air as it needs and if the stock airbox doesn't stop it drawing that air it's difficult to see how a bigger one will make any difference - like the 300 Fantic example, or my 320 Majesty?

This is one I made for a 320 Majesty using a modern airfilter but 175 could be done the same. I did it not for performance but for the ease of removing the airbox for maintenance because the original airbox is a lot of work to remove. Also it was broken. There was no difference with performance.

The puller I have is tapered so it doesn't damage the threads. The Ossa sleeve can also fly off pretty quick so at least you know what to expect after the Monty experience... Most damage I ever did was with a MAR rear wheel spindle. Because they used to bend (i didn't realise this at the time) they could be a bugger to remove. I had one stuck once, half way out and as an enthusiastic teenager employed the hit it as hard as you can method. I was absolutely battering the drift with a lump hammer and eventually it came out - like a guided missile it flew arrow straight across the garage and went clean through my dad's stock of flourescent light tubes, reducing them to powder in a nano second... I also put the front wheel of the same bike through a french window following a badly executed pivot turn off the step up to it. Had to say I did that with a plank of wood.

I don't understand why? I could if the engine was struggling to get air due to the airbox restricting airflow, but it doesn't. The TY175 engine doesn't have flat spots and it will rev out cleanly so it must get enough air. A larger airbox won't allow it to draw more air than it needs? The airbox on my KT250 was smaller than a TY airbox but still provided the 250 motor with enough air. I've ridden a 300 Fantic with a large volume airbox and flatslide carburettor and it was no more powerful than a standard bike. The standard bike actually felt better...

Tubeless tyres don't seat well on the Japanese tubed rims so you're going to be taking a gamble if you try and use it. Even if you get it to seat when fitting, you run the risk of it dropping into the rim when riding. Usually, after fitting, they drop off as soon as you let the pressure down, normally around 10psi

Actually it was a very stable bike and was brilliant fun on the road. Gave a Golf GTI a hard time round the switchbacks of Moidart one year and had fun with a bunch of trail riders on big KTMs another. I'd punctured the rear up on the Ben one year and didn't have time to fix it but it was also doubtful I'd be able to limp back to FW in time either, so I'd resigned myself to exclusion, having had a miserabale week fitness wise with back and wrist problems. Anyway, coming down off the Ben, Alan Sagar was just about to set off having seen Paul through. He flagged me over and offered me Paul's spare wheel to get me back. He set off in the van leaving me to fit it. Never forget his face as I steamed past his van a few miles further down the road. The rear had 20 - 30psi in it and the TYZ was really singing on that occasion. Worst bike I rode in Scotland on the road was a '98 315 which wanted to knock itself apart during roadwork and needed constant throttle adjustments to keep it running clean and from knocking. The 4RT was a huge improvement over that thing and was quite relaxed on roads and forestry tracks.

Unlikely those were the original bushes as they would normally be a bronze bush with a steel inner sleeve. Yes it will have to come out to fit new bushes, you can get the complete kit from Bultaco UK - bushes and spindle