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Ossa mar clutch


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Hi, after finally finishing the rebuild and starting it up I've a problem with the clutch. At first I thought that the plates were stuck together but it's the action that's the problem. I pull in the lever and it stays there until I manually pull it back. It's a new cable, so I don't think that's the problem. Any ideas gratefully welcomed. 

Also the carb seems to be in need of adjustment. There only seems to be one screw that I can see, it's on the l/h side of the carb but I thought that it was the idle adjustment. The bike starts fine but if I stop it and try to re start it won't unless I remove the plug and clean it.

Help!!! 

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not enough info. is the handle bar lever springy, ie, can you feel it operating the clutch? if it is but the clutch don't dis-engage, yes the plates could be stuck. but that wont stop  your lever returning. is the hinge bolt on lever too tight? is the lever on the mag cover springy???

as for the carb, what is it? we need a few clues!!

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Sorry, the lever isn't too fastened on too tight. You can't feel anything!! It just pulls back, really stiff, then stays there. The only way that I can tell it's disengaging is that when you try to kick it over with the clutch lever in there's no compression.

The carb is a mikuni.

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If you remove the cable at the clutch lever on the engine- then move the lever (have to use something to lever it)- does it come right back?

could be too large bearing in the middle? (I would thing you would notice it didn't just fall in). 

I would probably pull the primary cover off and take a look- it isn't a big deal and then you will really know. Plus you could dismantle the clutch to inspect and make sure it is back together correctly etc.

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I had a Mikuni on my MAR, it came with 150 main jet , and 35 pilot. You might need to experiment with other size jets, for correct running.

The mixture screw is on the right of the carb, it is slotted brass facing up at you when on the bike. Should be about 1.1/2 to 2 turns out, with hot engine.

 

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At least we now know it is a flange mount Mikuni, which narrows the field a lot. Most Mikunis are spigot mount. A photo showing both sides would make it easier. To measure the "size" of a carby you measure the venturi diameter, which requires taking it off the bike

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  • 2 weeks later...

Right, eventually found time to take off the carb....it measures 27mm!! There's a 3.0 stamped on the needle slide. Hopefully I've managed to add a few pictures. The only thing that I can find wrong is that the o ring which seals in the float chamber is perished. Also now that the tank is fitted the carb leaks! I've cleaned the float needle and housing so hopefully it's sorted. I'm still unsure where to adjust the mixture, is it the small screw to the right of the idle screw?

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