I have a 2000 200 merc efi, I checked compression and have 110 in 4 cylndrs and 111 in the other 2. Is this good, bad, what? would it be better to run 93 octane in this motor, or will there be a difference from 87 or 89?
I wouldn't run higher octane gas. I've heard the higher the octane the slower it burns and that it can cause more carbon build up on the pistons. Is the motor having performance issues?
Those are good compression numbers but a leakage leakage test is a better indication of health. I have build several engines that had good compression but have had high leakage. </p>
That one should have a emission label on the VST and state 87 octane. Just my .02</p>
