Hello lads,
I have been chasing an oil leak from beneath the alternator cover for a few weeks unsuccessfully, and it was suggested to me that the problem could be excessive crankcase pressure, eg the breather is not working properly. I took a quick look tonight and the hose from the breather atop the valve cover was somewhat pinched as it made the turn down , but not terribly. I then removed that hose from the reservoir below the airbox and blew compressed air into it with the oil fill cap loosened. It flowed air fine, which would suggest that there is not a blockage in the breather itself.
I removed the alternator cover, cleaned out what oil remained in the small chamber at the bottom with the weep hole, reinstalled it, left the upper breather tube disconnected from the reservoir, and fired it up. Still leaks.
Previously I removed that oil gallery plug underneath the alternator cover, replaced the o-ring and reinstalled it with a smear of 3-bond, and so I do not believe it is coming from that area, although I am not 100% certain.
I think it is possible that there WAS a pinch in the upper breather tube, which could have resulted in excessive crankcase pressure, causing oil to pass through that left crank seal behind the rotor.
And if so, I suppose the question is, is that seal now likely crap, having been exposed to excessive crankcase pressure for 30 or so miles of break-in riding?
Second question: How hard is that to replace? If I remove the engine and flip it, can I remove the bottom crankcase half (having removed the clutch and alternator covers) and access it without removing the cylinders?
TIA for your thoughts, or just your speculation at this point. I am scratching my head.
N.
