Oil on spark plugs

[boatman1959]

Hello, I have a 1990 evenrude 225 on a 26 foot deck boat. It use to go about 32 mph and I never had a working tach so I dont know the rpm but now it will only go about 22 mph and whenever I check the plugs they have oil on them. I have changed the plugs , wires , and used some power tune, but still a lack of power. I even checked the compreshion and it was 85 for a high and 79 for a low. I would listen to any advise on what else to check. I have also checked to make shure that all coils are firing.<br /> Thanks

 

[12Footer]

Re: Oil on spark plugs

Those compression numbers are mighty low. I would try another gauge to confirm the results, as this could be your primary cause of performance loss.<br /><br />Also, try a spray decarb treatment to see if compression improves. At any rate, it sounds like you may be on to the culprit, if performance loss was a gradual thing.