I have a 2006 40 HP Mercury Lightnihg XR. Under load it revs high and there is no prop power to get to the plane. Plenty of water is being churned up, but no power.
I thought it was the propeller slipping so I replaced the propeller. Same thing.
It seems to be cavitating all the time when it gets under load and adjusting the trim so the prop is more towards the surface does not seem to have any effect on the problem.
On a good no waves, no wind day, with my wife up the front it seems OK an now and then overrevs like I've hit something.
It seems that the boat is full of lead, but I drained all the wave water our before my test run.
On land it runs fine. When stopped and in gear, there is good drive when I turn the prop and no slackness.
No unusual noises from the engine, just churning up lots of water but no push power.
I thought it was the propeller slipping so I replaced the propeller. Same thing.
It seems to be cavitating all the time when it gets under load and adjusting the trim so the prop is more towards the surface does not seem to have any effect on the problem.
On a good no waves, no wind day, with my wife up the front it seems OK an now and then overrevs like I've hit something.
It seems that the boat is full of lead, but I drained all the wave water our before my test run.
On land it runs fine. When stopped and in gear, there is good drive when I turn the prop and no slackness.
No unusual noises from the engine, just churning up lots of water but no push power.