Looking for some advise OMC 225 HP

[bbay15]

Hey Guys,
Im thinking of shaving the heads on my 1989 225 Johnson to gain a little more compression(currently running around 100 psi in all cylinders).I was wondering if I will have to re-jet the carbs,also if I can do this without re-jetting how much do I shave the heads.
thanks in advance :cheers:

[Jim_Pat]

I can tell you what I did about 20 years ago. At that time the 87 heads were still available. My stock compression was 90lbs on all cylinders stock. The additon of the 87 heads (120lbs compession), increased the jet size by 10 and removing the inner baffle in the air box really woke the motor up. I also bumped the timing up but better gas was available then. This was on a 20' closed deck Concord. (Little Rock Arkansas) This perked up the motot quite a bit from stock. Not sure on the speed but would guess a honest mid to upper 70's (74-76) the speedo always showed more. This was on a GT200

[BeefKid]

i cut mine bout 60-80 thousandths and it helped out the hole and everything... i did it on like an 83 200... it makes a differnce

[racer]

Beefkid I am assuming you meant 93 not 83 as that would be crossflow. The 86/7 225 head would be the best option on a 88-92, they flow much better than cut stock heads. You want ones uncut (chamber depth .700) and increase main jets 2 sizes while leaving the airbox stock.

[bbay15]

Thanks for the info guys...wont be doing it right now (still 3 feet snow) but something to look forward to.Current setup on a 21'Hydrostream Voyager,6" setback,running 1" below pad,lwp,nose cone...probably 72mph, stock engine,relieved exhaust below base,running 28pitch chopper.Looking to get a little more mph.

thanks again

[NosBoss]

Would I have anything to gain by cutting the stock heads on my 1987 200xp? I know I already have the desired heads so changing them is out. Last I checked my compression was around 90 psi.