i have developed an oil leak between the upper & lower piston casings...someone told me that there is a gasket in between them...this motor was sitting for a while when i bought it , so i am guessing that the gasket got a little dried out from sitting and now tht i ahave ben runnin it, it's leaking...is this a tough job to replacethis gasket....any info would be very helpful, thanks...ride safe..