montesamadness

Neil - I don't want to position myself as any sort of expert here but I think that might be a 349 not a 348. I say this because I think the 348's had frame rails running under the engine with a bash-plate bolted under them, whereas the 349 had no lower frame rails and used the bash-plate (and engine) as a stressed member. The photo isn't totally clear, but that's what it looks like. I'm sure someone with more experience will be along to give you more info though. I think the 348's were actually 306cc whereas the 349's are actually 349cc. Good news for your right-leg muscles! As long as it turns over (even if it doesn't run) and selects all (6) gears correctly then I reckon you'll be safe paying 800 for it. Even if it needed a new piston/ re-bore AND a crank rebuild you'd still get your money back (as long as you did the work yourself), 'coz it looks pretty complete apart from that....

When I was rebuilding my 349 I found scraps of info on the web but not much. There's loads of knowledgeable people on here and I learnt loads simply by searching through previous posts. In the end I did manage to get a workshop manual, but it isn't a lot of use apart from basic stuff like torque settings. If you need to strip anything down in the motor, your best bet is to take your time, be methodical and take loads of photos. Aside from the (slightly weird) motor, the rest of the bike is totally basic and you could probably put it back together with your eyes shut!

Hi Neil I might have come across a bit negative about the old Mont's there! A lot probably depends on how much you're paying for it, and how handy you are with the spanners. I bought mine for a hundred quid with a seized top end 'coz the guy couldn't be bothered to fix it. I've put about 400 quids worth of parts and well over 100 hours of my time into mine, and it's still scruffy and needs new tyres. It's great fun to ride now it's done, and I know the bike inside out because I've rebuilt every nut and bolt of the thing. And in a weird masochistic way I enjoy the ongoing tinkering! If you're in a similar position and enjoy a mechanical challenge then go for it. But if you're paying market price and you're gonna pay someone else to spanner it then forget it - you'll never get your money back on it 'coz these old Monts don't seem to be worth a fortune (sadly) And if you just wanna ride a (properly engineered) bike, and stick to routine maintenance then buy Japanese!

I wouldn't bother if I were you. Mine's way too powerful, and it's a b@stard to kick over when you're tired!

Hi Netley In answer to your original question, most parts are readily available from the likes of InMotion trials in Surrey and others, and parts regularly surface on ebay. However..... If the motor needs a rebuild then you're in for some "fun" 'coz it was designed by a complete sadist! If you need to split the cases/ do the crank seals you'll need to make a special puller to get the primary gear off and it's a b@astard of a job. Other little gems include a shimmed up crankshaft and gear cluster, gearbox sprocket driven onto a taper, L/H thread on the ignition flywheel, barrel nuts recessed into the cylinder (which then rust solid so you can't get the barrel off), weird-a***d gear selector mechanism with strange "adjuster".....the list goes on!. I've just finished rebuilding a MH349 (similar engine, just a bit bigger). Now it's running I love it and it's great fun, but there were times when I was rebuilding the motor when I thought I was going to cry! And if I ever meet the guy that designed the motor (unlikely I know) then I definitely won't be shaking his hand....! Good luck!! Gavin

Ant - I can't speak for a 248 because I've got a 349. If the 248 is similar to the 348 / 349 then the brass plunger is a piece of pi$$ to change. It takes longer to get the side casing off than it does to pull the plunger out. With a clean bike and a new primary gasket and brass plunger, it's a 5 minute job from start to finish

When you say it's dragging, do you mean it actually creeps foward with the bike in gear when the clutch is in? Or is it just hard to find neutral at a standstill? I ask because plenty of people (myself included) sometimes struggle to find neutral at a standstill - it seems to be a feature of these bikes. If it's really bad, there's a few bits you can check without opening the side case, as follows: # Stretched clutch cable # Badly lubed / knackered clutch cable # Bent clutch lever # Bent clutch actuating arm (the bit that comes out of the top of the side casing) If none of those solve it, pull off the clutch side casing and check the little brass plunger that sits in the side casing - it might be worn (you can get new ones from InMotion trials) thus preventing the clutch fully disengaging. While you're in there, have a look at the three-legged "spider" that the brass plunger pushes against - it might be bent. If it is, this would also prevent the clutch disengaging properly. Good luck!

I've had a couple of cranks done by Grampian Motorcycles in Liverpool. www.grampianmotors.co.uk. They've done a good job on my multi-cylinder cranks, so should have no probs with a single

Hi Dan There's loads on here about this, but this is my two penneth' worth. I ride a MH349 (same engine, just slightly bigger) and run 10w30 semi synthetic in the clutch and SAE90 in the box. Some people suggest using monograde in the clutch to prevent slip but it'll only slip in the high gears anyway (if it slips at all) and you're unlikely to need them in a trial Hope that helps Gavin

Hi Stichillist I've just finished rebuilding one of these and the gearchange mechanism was one of a few areas of the bike that caused a fair bit of frustration (to put it politely)! One thing I found is that when you're setting up the gearchange mechanism and doing a static check to make sure all gears select correctly, you need to rotate both the clutch and the gearbox output sprocket (or the rear wheel if the chain is still attached) while you're doing it, due to the relatively large movement of the selector forks within the crancases. I did this as part of an engine build so it didn't have a top end at that point. As your engine is complete, you'll need to remove the spark plug to reduce the compression as you turn the engine over I'd recommend that you take all the external selector mechanism off, so you've just got the end of the gear selector drum staring at you through the oil seal in the L/H crankcase. Then use an 8mm open-ended spanner on the square of the drum and check you can select all 6 gears whilst rotating the clutch and gearbox output sprocket by hand. Once you know that all 6 gears select, you can then assemble the external selector mechanism and fine-tune it using the eccentric adjuster. It's a bit fiddly, but once you get it right it's actually quite satisfying. Keep us posted.... Gavin

After a bit more tinkering over the weekend, I thought I'd give you all an update, as I'm sure you've been waiting excitedly for the next installment....or not! I took a bit of inspiration from your KT silencer mods Feetupfun, and had a nose inside the WES tailpipe. I found that the part of the silencer that has packing in it only extends about two thirds of the full length of the tailpipe. The first third (furthest away from the tailpipe exit) is an empty chamber and the only silencing in this section is the fact that the inlet to the chamber is at the bottom, and the outlet (the perforated tube that runs through the rest of the silencer) is in the middle. In other words, the inlet and outlet don't line up which (I assume) is intended to block the passage of sound. As an expirement, I extended the perforated tube all the way through the silencer and into this first chamber also. I then re-packed the main chamber with silencer packing, but much tighter. Amazingly this inspired engineering (or bodging as most people would call it) seems to have worked, and the bike is a fair bit quieter. I was riding with a guy on a TY250 mono at the weekend and my Montesa didn't seem any noisier than that. I don't know if that's a particularly good benchmark, but it's good enough for now. Moving foward, I might try angling the tailpipe downwards and maybe even putting exhaust wrap round the silencer if I'm really desperate (to look ridiculous), but now it's time to move onto the next job....fork oil seals. Just a final note to say a massive THANK YOU to everyone who has contributed in trying to help with my little silencing challenge. I'm sure I'll be back with another head scratcher soon....!

Cheers Feetupfun You sound like you've got a lot of bikes....excellent work! You say you re-modelled the internals of the KT250 exhaust to make it quieter- what specifically did you do to achieve this? Interesting you say about you using the TY175JC silencer. I did wonder about trying to put a KTM 2-stroke enduro silencer on my Cota.These are really quiet, and seem to sell for next to nothing on ebay, unlike the standard Cota 349 silencers which seem to cost a fortune.

Feetup - interesting point- thank you. Yes all my previous strokers have been water-cooled. One thing I've noticed though, is that the motor is actually quite quiet if I put a glove over the tailpipe, which suggests that my re-packing of the front box may have had more of an effect than I initially thought. Not sure the glove is a permanent solution though! Good point about the back-pressure. I'll have a bit more of a tinker with the WES tailpipe, but I won't do anything too drastic. If I can't get satisfactory results then I might go for a secondhand original tailpipe as Cleanorbust previously suggested, although the bike already owes me nearly 500 quid in parts so I don't want to just keep chucking money at it. One thing I hadn't considered is how two-stroke noise travels through the air. Although they seem very noisy close up, the noise never seems to travel as far as four-stroke noise. The nearest house to where I ride is a good 300 yards away, and the nearest footpath is approx 80 yards away so I'm hoping that the (marginal) success that I've had in quietening it down might be enough. I'm wondering if I'm suffering from noise paranoia!

Right then, time for an update. Having spent several hours performing keyhole surgery on the front pipe, pulling the old wire wool out and replacing it with glass fibre wool then patching it back up I can report a small improvement....but not much. In desperation I wrapped the front box in exhaust wrap externally as well to try and add a bit more sound insulation. I also re-packed the (brand new) WES rear silencer. Overall, this catalogue of exhaust surgery has quietened the bike down marginally but I'm still not totally happy. Turbo, you're right - TIG would have been nice and neat. Only problem is I haven't got a TIG welder. And my MIG welding usually ends up looking like pigeon $hit! So I went for the easy (and easily removed) option and riveted the cover plate on with lots of messy silicone - no leaks there! Next stage is I'm going to try and knock up some sort of baffle insert (a bit like the FMF quiet inserts for four-strokes) and stuff that in the end of the pipe. Anyone got any thoughts / experience of doing this? Thanks everyone for your help so far....

Thanks 2s4s. Do you recall whether you cut the whole side of the box out, or just a small access "window"? I did try to get the original silencer, but InMotion didn't have any in stock and wouldn't get any until end of April so I went for the WES so I could get the bike running and shaken down. I realise it may be a bit noisier, but I want to get the bike as quiet as possible to protect where I ride (and my eardrums).