Expert: chris Wethered - 5/8/2008

Question
CHRIS, ON MY FIRST TRIP TO THE LAKE WITH MY BOAT, THE ENGINE ON MY BOAT POWERED UP AND RAN WELL FOR A LITTLE WHILE. UPON MY   THIRD TAKE-OFF,THE ENGINE CAME UP TO FULL SONG BUT THEN A FEW SECONDS LATER THE ENGINE SPUTTERED AND QUIT. I REFIRED THE ENGINE AND IT REPEATED THIS AGAIN ONLY QUICKER THIS TIME. AS THE DAY WENT ON IT BEGAN GETTING WORSE. UPON INITIAL TAKE OFF, I COULD GET THE BOAT TO PLAIN AND IT WOULD RUN OK AT ABOUT 1/3 THROTTLE. BUT BY DAYS END THE ENGINE WOULD ONLY IDLE.WHEN I ACCELERATED THE THROTTLE THE ENGINE WOULD BOG DOWN LIKE IT WAS BEING CHOKED. WHEN I GOT HOME I CHANGED THE FUEL HOSE,FUEL FILTER, AND SPARK PLUGS. I ALSO FOUND THAT THE BOTTOM CYLINDER PLUG WAS NOT FIRING. I TOOK OUT THE TOP PLUG, WHICH WAS FIRING, AND REPLACED IN THE BOTTOM CYLINDER AND IT WAS FIRING. OF COURSE, I REPLACED THE PLUG THINKING I HAD FOUND THE PROBLEM BUT THE ENGINE STILL DOES THE SAME THING. ANY SUGGESTIONS, I AM RUNNING OUT OF HAIR TO PULL OUT. THANX

Answer
Hi Brain,

i think the problem lies in the engine over heating. This as you know is to do with the cooling functions. You need to check that the impeller is working, plus water is passing around the cooling system correctly.

If the cooling system is not working then the engine cannot run, it ceases up, which is why it stops so frequently. Metal expands a lot and the cooling system is required to stop that from happening.

Let me know how you get on

Chris

PS

Over at boatpride.com we are asking for visitors to submit any problems they have regarding maintenance. This way we can solve problems and share knowledge. All you need to do is opt in to our E zine and supply your questions. We are giving out a free report on an E book by the Editor of Boating Magazine Frank Sergeant too.