Compression check question

With the engine warmed up, remove all spark plugs and prop the throttle wide open, crank the engine until it the gage reading stops increasing.

On a cold engine, it will be hard to tell what's good & what's not.

Some of the recent posts have numbers ranging from 140-185 psi. If the compression is low, squirt some oil in the cylinder and do it again – if it comes up, the rings are worn.

There should be no more than 10% difference between cylinders. Use a blow down leak test (puts compressed air inside cylinders) on cylinders that have more than 10% difference.