old trials fanatic Posted March 2, 2009 Report Share Posted March 2, 2009 Well it's happened to all of us at some time or other. Bought a pretty bike from somebody we thought we could trust only to find it's a total wreck once you delve beneath the pretty skin. This time it's my turn with my MAR. Only thing to do is bite the bullet and get stuff welded etc etc. Main problem that is really causing me concern is the crankcases are cracked around the gearbox drain plug which will have to be welded up. also the magneto cover looks more like a photo of frankenstien from the inside and has been welded, badly i hasten to add, more times than i've had fives. I know you can fit primary cases from all models including the Gripper because i know a guy who runs a gripper cover on his MAR but can you run a gripper mag cover also? I'm only asking because mag covers are like hens teeth and i need to fit something. As for the crankcases i've accepted i will have to get them welded as the rest of the engine will be shimmed up to suit these cases. Strangely it started and sounded ok till i tried to top the gearbox up then had a flood of oil everywhere. So will fit new bearings and seals and move on but i still need outer cases. Has anybody any experience of fitting cases off any other models? Quote Link to comment Share on other sites More sharing options...
brian h Posted March 2, 2009 Report Share Posted March 2, 2009 OTF A number of Ossa MAR crankcases complete seem to turn up on eBay (USA) from time to time, always usefull to have other spares - even if you have to buy a complete engine. The Ossa MAR engine is mechanically pretty tough from my experience, however, the alloy cases seem to suffer with intergranular corrosion over time and do not weld easily. I think the USA was a good market for the Ossa MAR bikes and spares in the 1970's and still the best source for parts. Try Ossa World website to start with, this web has a number of good contacts that may be able to help you. Hope this helps Brian H Quote Link to comment Share on other sites More sharing options...
woody Posted March 3, 2009 Report Share Posted March 3, 2009 Yes, a Gripper case will fit either side so no problem there other than they are harder to get than MAR cases unless you have one already of course. They just have a recess for the mag wires unlike the MAR which is in the actual crankcase at the bottom. On the Gripper it is in the top of the timimg cover itself so you'd need to plug that. I'd hesitate to say 100% that any case will fit, I'm pretty sure they will, other than the later motocross cases that are visually different and may be slimmer for the smaller flywheel. Virtually all other enduro and trail bike cases should do. Some early 4 speed models may be slimmer and not have enough room for the flywheel but I'm guessing here but they don't look right anyway due to the different design of the OSSA logo on the casing. As Brian says, there is usually a good supply of cases on ebay USA so worth having a look on there. Quote Link to comment Share on other sites More sharing options...
tony283 Posted March 3, 2009 Report Share Posted March 3, 2009 OTF, it just might be your lucky day! PM me to discuss. Tony Quote Link to comment Share on other sites More sharing options...
monoped Posted March 3, 2009 Report Share Posted March 3, 2009 Hi OTF, I have a mag cover for a MAR, it has not been cut down around the gearbox sprocket if you are interested. Quote Link to comment Share on other sites More sharing options...
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