Compression Loss, and Solution. 1979 AMF Harley-Davidson XLH1000 Ironhead Sportster

Pushrod adjustment is the problem nine times out of ten, but the tenth is a holed piston. A quick fix, once you master unclipping the pushrod tubes and keeping them out of the way. Getting them back on is fiddly as all hell. Pushrod adjustment is the easy part, just make sure you have both valves closed (lifters at the bottom of their movement) or you'll make it worse.