Hi, I'm having trouble sourcing a set of piston rings for a 1981 Montesa 248, the larger L shaped one on my bike has broken and they seem hard to find.
Has anyone managed to source any, or had the same problem and found an alternative.
the piston is the standard it's not been re bored and the cc is 239.3.

Many thanks folks.
Dave.

try inmotion they might have a piston kit , or i think ive seen a cylinder with piston on ebay

Thanks, Inmotion can't get them and the one on Ebay is piston etc but no rings, thanks anyway.

Dave.

look up the catalogues/reference material of current piston manufacturers and see if you can find a piston that has the same dimensions or can be modified to suit your cylinder. You will need to know nominal diameter, height from centre of pin to crown, centre of pin to base of rear skirt, gudgeon pin diameter and piston ring locating pin locations.

There are very few of those bikes in use so you may well be the first person wanting a piston for many years, so you might have to do some legwork

If you post up those dimensions, someone might be able to help you with the search.

If it is just the L ring you want, then you can measure yours up and search for one of them. I know there are still lots of new L rings out there for old Yamahas and Bultacos, and probably others had L rings too

If you are desperate you could have a new groove machined to allow fitting of an available ring, or have the old groove machined to suit an available ring, of the right diameter

Thanks Australia,

I've got the lads at Inmotion Bultaco UK, looking into alternatives from Bultaco etc to see if they're close.

I'll just keep a watch on Ebay for someone breaking an engine as well.

Your right there aren't many about these days, some 348s and 349s but very few 248s.

Thanks for your assistance.

Dave.

http://www.192.com/atoz/business/bristol-bs5/engineers-general/piston-broke-engineering/6a103b7698b8b0988f14bf36f6c62c88d621eec2/ml/

some one else to try . kevin breedon racing, look him up on google

try jarod bates at south west montesa always very helpful

ps:your old tr35 is now up and running and has even done a few trials

regards Paul

Hi Paul,

Glad you got her going, did you manage to find some tank decals in the end?

Thanks to all for the advice I'll get onto Southwest Montesa tmrw.

Dave.

Hi Dave

No I Havn't sorted the tank out yet been using the bike fairly regular thought giving my old montesa a break

Your best emailing jarod tonight as he is in Arizona but if he has the parts the service has always been second to none good guy for advice as well

Regards Paul

Thanks Paul,

I'll email him tonight, thanks.

Thanks Spusdad, got hold of Kev at Kev breed on racing and he's pretty confident that he has got some that are almost identical.

Paul, contacted Jared but he only had first oversize and no standard bore, but a good contact though.

Thanks to all,

Dave.