Loud thunk when wide open

[newbyforce]

My 85 horse Force engine, when wide open occasionally "clunks" violently. It allmost feels as if the engine is hitting something. A loud, transom shaking knock. Doesn't happen at 3500, but 4500 RPM's or so it's every thirty seconds or so.

Any ideas as to what this might be?

Thanks much for any insight.

Dan

 

[racerone]

Could be the clutch dog in the lower unit is worn / out of adjustment-----------Best to check it before something really breaks.

 

[newbyforce]

Thanks for the tip. I'll check that. I've got a manual that should get me there.
Merry Christmas.