225 efi

[bigobass1]

Got a Merc 225 efi and want to raise compression approx 25 lbs.Want to know how much I can cut the heads safely? I generally cut 10 thousandths but I don't think that would raise it more than 10 pounds.Thanks, Bigo ;)

[Simon]

What year motor?

[bigobass1]

It's a 1999

[Simon]

64cc's will be around 125psi , promax 300's are 67cc's

[bigobass1]

This is a fishing motor on a 25ft center console I'm trying to bump the compression on. It's got 108 even on all 6 which is lower than I like to see but other than a little weak out of the hole it runs good. You know 3.0 motors,do you think cutting the heads 15 would leave me enough clearance? Thanks

[Simon]

lighten the flywheel. It will help the hole shot and acceleration. The heads on that motor are oringed.