CaribeSurf

Well, is me again. The mechanic I took the boat to did install a new kit on both carburators, including the small filters. Last week I spoke to the mechanic about the problem I was having and he recommended a couple of things I should try next time I drop it in the water.

First; to start both engines and run for a few seconds before the boat goes in the water. Something to do with fuel tank pressure causing the carburator to get flooded. Second, once in the water to let the engine cover open and look for water being sprayed over the carburators.

I have not done either one of them. I discovered, after washing the engine compartment, that both front engine mounts where broke on, of course, the right engine. After removing the exhaust manifold I began working on the mounts. As I was wrenching around I noticed a fairly thick black cable broke off from somewhere under the engine. After tracing the cable I realized it was the ground cable that attaches to the starter bolt.

I replaced the mounts and re-installed the ground cable. Started both engines and they sounded good. There is a good possibility the ground cable was not doing a good job at grounding and could have caused the spark plugs to miss occasionally. I guess I will find out next weekend when I drop it in the water.

Thank you for your responses.

This is what I have done so far. I took the boat to an experienced mechanic and he, after inspection, recommended overhauling both carburators. He also changed a 3/4 moon disk he said act like valves and a couple of exhaust gaskets. He tested the boat on a calm river and both engines worked fine according to him.

It was my turn to try. I drop it at the beach, the same engine began running the same way as before (like on one spark plug), would not go pass 4K rpm's. Both engines idle great. About 10 minutes later it started to sharply increase and decrease in rpm's until all of a sudden it went to 7k rpm's and stayed there for a hell of a joy ride.

After a couple of hours and a few mandatory rests; your body takes a beating on the ocean waves, I went for the longest ride of the day, everything ok. At one point I noticed my fuel gage and I was right below quarter tank, so I decided to turn around based on the 1/3 rule. Once I was very close to the place I was anchoring the boat I decided to do a very sharp 180 deg right turn, and bingo the right engine (same engine) began doing the same, 4k rpm's max.

I have a couple of theories; one is that the ignition coil for that engine is what is called tired and when under stress fires only one plug. The second theory is that the gasoline is dirty. I replaced the filters attached to the panel. The old ones, specially the filter for the right engine, where very dirty. Didn't try the engine after replacing fuel filters.

Any comments.