Question about 1989 Yamaha FZX 750

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I have a 1989 fzx 750 and there is oil leaking through the alternator,,any ideas,,also is there a breather hose on the engine thats supposed to be releasing little bits of smoke ??

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Sounds like you have too much crankcase pressure.
That may be caused by excessively worn rings or valve guides, a hole in the top of a piston, or a crack between a cylinder wall and the crankcase.
All of which are pretty serious. The leak at the alternator is just a blown seal but the crankcase pressure must have been high for it to blow. first, carefully inspect the breather hoses from the crankcase and the cam cover to atmosphere. if they are kinked or plugged, that will cause the symptoms you describe. On some bikes there is a hose from the crankcase to the intake box. Be sure this is not blockes. Some bikes have a PCV valve, check that.
good luck.

Posted on Jun 16, 2009


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Jun 10, 2009 | 1989 Yamaha FZX 750

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