No idea on your compress gage without knowing more about it. If you can hold the compression back easy with your finger I would say the gage is OK and you have a engine problem. I know my compression gage has a one way check valve in it and sometimes gets dirt or carbon in it and I have to clean it. If this is the case the needle should jump as you turn it over, Also as said before check the release valve is not open. Are you getting a good seal around the plug hole? Is something pluged? Was the gage just banged around in the bottom of a tool box on the back of a lawnmower for the last 10 years and just no more good? I don't know what more could go wrong with a compression, anyone got more ideas. :wink:
