I checked the compression on my engine yesterday, I have 120# in 1-3-4 and 90# in 2. Is there any way to tell if my problem is rings or valves?
I checked the compression on my engine yesterday, I have 120# in 1-3-4 and 90# in 2. Is there any way to tell if my problem is rings or valves?
Squirt some oil in the bad cylinder and test again. If the compression rises you have bad rings, if not it's a valve leaking. Always make all compression tests with all plugs out and wide open throttle.
Looks like I have a ring problem. Compression went right up to 150#.
Don't despair till you've tried a couple tricks. This only applies to an engine that has been inactive for a long period. Soaking the rings with a good penetrating oil might restore compression.
If you can get the compression high enough to start, warming up the engine then letting it cool with penetrating oil added, might soak in more. I have brought back engines that were near zero compression on several cylinders, I used Pete's approach till I got enough compression to get it started then did several start/warm/penetrating oil cycles over a few days and got back compression.