Busted a couple of power valves, replaced them but I still have low compression 40 lbs in #1 and 65 Lbs in #2 cylinders. Pulled head back off and nothing looks bad, no cylinder scratches, hone marks still show all around both cylinders. Put micrometer on both cyls and they are not ovaled out or worn. Can't figure out how to do a compression leakdown test on a 2-cycle as the piston will push down and open the exhaust port. In the old days you were able to put oil or PS fluid in the cylinder on the piston and see how long it took to drip past the rings. Is there something similar with these 2-cycles ??