My 5hp flathead has been leaking oil for quite some time. I checked the crankcase gasket and that seems fine, and the flywheel and that area is fine, what are some areas that the engine leaks? Thanks for the help.
Does it leak with the engine/bike sitting level? If not, it might be the oil filler cap (if at the bottom of the crankcase cover). I had a similar problem with a Tecumseh and traced it to the filler. I went by the hardware store and picked up a fiber gasket and that seemed to fix it. Another common problem is the oil drain--snug it a bit tighter than you think you need to--had that issue on another engine.