I recently solved a problem I think many have had, or will have. Had to boat out last weekend for a shake down run. Engine would run perfect up to around 1800. Above 1800 started smoking, and would not rev above 2100. Any advance of the throttle above 21 or 2200 resulted in only black smoke. Lots of smoke and some soot in the water. A couple of different ( More Knowledgable I Guess ) said it was a dirty prop. I didn't really buy that. First off, the bottom was done last June, and splashed July 1. Bottom is spotless, and have never had a big barnacle problem where the boat stays. I have had barnacles on a prop before, but did not act anything like this. So, after all the other possible fixes, I dove and checked the prop. Barnacle city on it. Covered with barnacles, as big around as a quarter, and 1/2" tall. Cleaned prop and problem solved. So, the voice of experience says don't assume anything. Because you have not had a barnacle problem before, don't mean squat.
