Sorry too early in the morning for my brain!
Only effects the reading if you do the test throttle closed....which is not the correct way, should be wide open throttle. Your reading should be correct
False reading with compression tester
Re: False reading with compression tester
Okay that makes sense, I thought I'd missed something silly
Re: False reading with compression tester
On a more positive side, front and rear cylinder are both reading the same 
