My motor case cracked on my last hunt. No signs of an issue other than slight gasket leak on the right side of the motor (facing prop). I did notice a single case bolt broke off at the threads and had rattled out. But it has been that way for near enough all of 2017.
So...anyone have an idea as to why the case cracked? I've never had an issue with a case. 108 hours. SETX heads. Marshmallow Exhaust. Mikuni Carb. Mods were done at 25 hours. Compression after mods was 160 in each cylinder. 22% and 10% leak down on the valves.
Lots of vibration in the motor now (obvious). Crack is on top of the motor case from the top right bolt. Also has a small crack at the middle case bolt, left side.
Any help would be appreciated. Obviously need a new case, but wondering what could've caused the crack. Hopefully nothing wrong with it internally. Only drove it back from the hunt the day the motor cracked (idled back
). Thanks in advance.