Am wondering if anyone else has the above problem. At varying RPM;s the boat will surge and then drop back on the RPM's. Only have 36 hours, winterize every year.
Pulling a skiier is out of the question!
Somewhat reminiscent of a car engine running on 7 cylinders versus 8. I pull the boat with a 1968 Mercury Monterey.
Initially was told using fuel with ethanol the past four years was the problem, but several cans of sea foam in the tank didn't solve the problem. Spark plugs aren't the issue.