CaribeSurf

Hello to everybody. I just purchased, my first boat ever, a 1997 Speedster, with twin Rotax 720. The boat is not in great shape but I got a good deal on it. I assumed I would have to do some mechanical fixes to get it running where it should be but I got to a point where I'm over my head. I live in Puerto Rico and we have a lot of ocean to run on.

I tried testing the Speedster in the water (ocean) before I bought. However, the engines started but they would not rev-up. The previous owner was moving to mainland and didn't have time to get it checked out. Hence the good deal. I later found out that the neutral switch was the problem and replaced it. Out of water, both engines started and rev-up nicely (in foward mode).

I dropped it in the beach, both engines started ok, and the boat ran like crazy for about 10 minutes, when the right engine quit. I was able to get it started but it sounded like it was running on one cylinder. Changed spark plugs but didn't improve any.

I pulled it out of the water and a friend check for current at the spark plug. He advised me to replace the spark plug cable on one cylinder. I did. I also put new spark plugs again. I started it and after cleaning up a bit it rev-up good. I dropped the boat on the water, again, and within a couple of minutes it began doing the same thing. I tried starting it again but I guess it was flooded and it didn't start.

The left engine is running fine, but I noticed the exhaust manifold had a small hole in what I guess is a water seal. The water was being sprayed actually over the front spark plug of the same engine and it did not seemed to be hitting the right engine, which was giving me problems. I sealed the hole with epoxy but did not try anything else since I had to wait for it to hardened. There are no obstructions in the impeller housing.

Does anybody have any suggestions on what could be causing this? By the way; I checked compression on both engines and the right is the best with 145 psi.