Hi there. The low compression can certainly make the engine run hotter. In order to get enough power to do what you're used to, you find yourself having to open the throttle more to compensate for the engine running less efficiently. That lost efficiency is power wasted in the form of heat. This is true for all engines. If you find the engine is blowing out a lot oil more than usual it's probably worn rings. It can just as easily be burned valves, usually the exhaust. The thing to do is find a way to lock the flywheel when the piston is at top dead center compression stroke and apply compressed air in the spark plug hole, 15 to 20 psi is enough. If the exhaust valve is leaking you will feel and hear it coming out of the muffler. If it's an intake valve it will be evident at the inlet of the carburetor. If it's rings it will be evident at the oil filler, although some leakage here is expected. I'm talking about a very noticeable amount of air escaping. Do this on both cylinders making sure both spark plugs are out during the test.
The simplest way to lock the flywheel is to put it in high gear. My money is on the exhaust valves.
Dewey
