Hi guys, I'm completely new to trials, well motorbikes full stop. There's been what I think is an Ossa MAR 250 sat in the shed for the best part of 20 years now, purchased by my old man for a tenner. As I've got a bit of time on my hands I've started taking it apart with the hope of getting it back to somewhere decent nick (never worked on a bike before but I'm a fairly competent mechanic and engineer).

I haven't got as far as checking the frame and engine numbers yet to find out specifically what model it is, I was just wondering if the pattern on the tank is stock? Most of the early models have the green stripe of some sort but i recently saw one with a red stripe? Unfortunately it was just a picture online with no further info. Also wondering if Ossa rims/hubs are easily identifyable, eg stamped?Here she is:

Most of the parts are non-stock, I'd like to get it back to as original a specification as possible. Any help much appreciated!

bit late now,stripping bike down to do up is wrong way round.best way is get it all sorted first,get it running nice,do some trials more sorting out,replace parts as you go.then strip it and do up.

Not sure I follow your logic mate. The brakes don't work, the spokes are rusted out, electrics are shot and it hasn't run in probably 25 years, so without stripping it down it's not gunna be running nice, or at all. No point doing it twice, just do it right first time

I know nothing about Ossa bikes but looks interesting...I would do the same as you and strip it down and start from the frame up...hope you have fun on the project!

Definitely, most of the frame looks alright. Cheers mate, sure I will do!

From the front forks and tank it looks like being a Mk1, though as you say many of the parts are not original. The good news is if your pockets are deep enough most parts are readily available, try Steve Sell Steve Sell <steve@marlimar-uk.wanadoo.co.uk> or Dave Renham at Inmotion.

Good luck with restoring it.

Do you know if the red stripe on the tank is original or has it been repainted? My pockets are pretty shallow at the moment so aesthetic things like fenders can probably wait, I'll concentrate on getting the engine, wheels, forks etc original and working. Thanks for the contacts, no doubt they'll come in useful

Agree with Mick, looks like a MK1 from the swingarm length, rear silencer, unpainted hubs and forks. Also the tank is the factory fibreglass one whereas the MK2 onwards in the UK had an alloy tank fitted, plus the side panel under the seat had a toolbox from MK2 onwards. Admittedly those things could be changed but they tie in with the other things.

MKK1 also had bolt on carburetor mounting to cylinder and the outside fins each side of the head were split not solid.

The engine number will confirm the model, most MK1 bikes didn't have the frame number stamped on them, it was on a sticker on the headstock which is usually long gone. The engine and frame number matched when built so you can use the engine number to check against the frame number charts that list the various models.

http://ossa.2y.net/o...a-frame-nr.html

MK1 Ossa

They were only ever white and green as production bikes. Mick had a red stripe on a works bike.

Edited May 29, 201313 yr by woody

Awesome post woody, very helpful. I'll get on with checking the engine number asap. ^ That picture is spot on, the MAR looks so nice. I'm in two minds as to which colour to paint the frame / hubs, either both black or silver frame with polished hubs, as per the original. I suppose it should be the latter really for maximum anorak points