Yanmar 62hp stalls 3 times

[jolie]

My Yanmar - although 4 years old has only 100 hours. I doubt the filters were ever changed, and I bet even the fuel is "original".My 5th trip this season, the engine stalled during cruising at approx. 2700 rpm about 3 times.Each time it started fine and ran for about 5 minutes. Then all cleared and it ran for an hour and is running now fine.The fuel tank is 1/2 full.Is this water condensate in the fuel?Do I replace the fuel filters? Or just drain the water? I wont drain the fuel, but is there an effective fuel additive I should add to the tank?

 

[Gordon Torresen]

Stall and restart

It is highly unlikely that water stopped the engine and then let it restart. Usually if water gets that far along you are down for a while. Your problem is more likely air inthe system. Your 4JH2-T is self bleeding and getting excessive air can shut it down or reduce the RPM, depending on how much air it gets. A fuel tank half full can see air getting to the pick up tube if you are motor sailing or even just motoring in slop, like one might experience in Raritan Bay. You do question if you shoud drain off the water. If you have water to drain, you have water in the tank that must be removed. Additives won't do it and they may cause more problems than they try to cure. Get the water out. Repair the cause of the water getting in, probably through the fill cap O ring. Top off with quality fuel and keep it dry (from water). Stay away from additives of any kind.