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When a piston ring pack becomes gummed up from bad fuel the rings stick in the piston grooves, then everything starts to go badly. Once you experience it you will know why I call it a jam sandwich.

Lemur what do you mean with jam sandwich?

I’ll take some pics of both tomorrow.

Thank you!

I’d be checking the internal diameter of the con rod small end. Even with the slightest play it will give a knocking noise. The piston doesn’t do much other than support the rings, which do all the hard work and wear considerably. If the con rod is slightly out of specification everything will wear as it won’t be runnng true and it will do the same again

You can use the TY175 head or the DT175 head. If you use a DT175 head, the compression ratio will be higher but you may need to trim the head fins for exhaust pipe clearance. You can mount a clutch cable holder on the engine casing or on the bottom cylinder fin. The DT175 cylinder fins will not interfere with anything physically. Trim them if retaining the original TY appearance is important to you.

Yes, think it made bike a bit crisper off bottom end, it was a 250 though if your looking to try one pm me, i have one i will sell, bike now sold & retired from modern riding!

Got it. In case I'm going to use DT175 cylinder - - Do I need to use DT175 cylinder head? - is it possible to make a new thread for the clutch cable holder? - Do I need to trim the fins? thanks.

DT175 1974,75,76,77 (DT175 ABCD models) cylinder will fit and function well but has different finning outline to TY175. I have not tried or measured up a CT1,2,3 cylinder.

Which brake plate is standard/correct depends on which hub is on your model 92. Also, they might both function OK. Can you do photos of the hub showing the brake drum and an external view showing the finning and both spoke flanges?

Also how should the brake plate fit the hub? And if you have some pics of the fitment that would be awesome. Thanks

Here comes some pics of both rear brake plates.

In theory; your piston wobbled because of either tightness in the wrist pin bearing or a jam sandwich in the piston rings.

Hello I have a model 92 Sherpa T 350 that I purchased as a basket case. I am trying to figure out if I have the correct rear brake plate. I have 2 rear brake plates but don’t really know how to tell if one of them is correct or not . I believe mine is an early 70’s model. Any help or pics you can post would be appreciated. I will see if I can some also.

What is my best option for alternative cylinder (barrel) for 1975 TY175 USA? DT175 or CT175? Or maybe something else? Thanks

Did anyone tried an upgraded injector in a montesa? Banyeras is selling en injector that should be better, does this just replace the stock injector or does the bike needs remapping to get the best out of it ? Kind regards Bob

that might be correct! parts are at the mechanic i tought it was a steel liner inside the cylinder but i only have seen the pictures

Just push your bike home, bump start it, or call a tow vehicle 🤣 says the 200 pounder who only rides flatlands and quad trails.

Here's the OSSA cush drive puller photo

Yes, quite impossible. "Fingers" on a puller made to fit in there are not strong enough for the job by a large margin. The puller needs to pull on the whole surface. The Montesa primary drive crankshaft gear of the same era as the OSSA cush drive is also on a taper and is also impossible to get off with a universal puller so it is not just OSSA who did this back in the day. I'll post a photo up later when my cloud storage is talking to me

Keeping the grey beards happy, probably the only ones that can afford to buy and also have the time to use a new trials bike at the present time.

Ok guys, can we just stop & have a reality check here ? Is this another answer to a problem that never was ? This modern world is full of ‘em and somehow the world and his dog get drawn in. Electric starters on bikes are an unnecessary luxury item in most cases IMHO, perhaps acceptable on a large road bike, but small capacity machines of any type just don’t need them. FFS if you’re riding trials then you’re likely to have got legs and are reasonably fit. And the next thing they sell you are titanium bits to save weight !!! Wake up people, just buy a bike with a kickstart, I can guarantee that a few minutes rest will recharge your leg, without needing to carry a backpack with anything at all in it. If your bikes got a fault & doesn’t start then pushing it back to van/paddock will be easier without an extra 2kg of starter and a another 5kg backpack. Sorry but my getting old, ‘Victor Meldrew’,(That’s a uk comedy reference, look it up) good old times syndrome just overcame me 😂

You sure you want to hone a plated barrel 🤔 don't think you are suppose to do that.

I guess they do, but they probably already have the puller? Is it absolutely impossible to get the cush drive out with a standard 3 arms puller?