Boat motor problem

[Barnacle Bill]

Get one of those cheap in-line spark checkers from your local auto parts store and check for spark when its happening. Electronics can break down after getting warmed up.

[gabowman]

Mine done the same thing but I found out the jet had worked itself out on the side of the carb. Ran fine at low speed but ran like it was only runnning on one cyc. after giving her the gas. There is a jet on the side of both carbs you can see from the side of the carbs.

[speck chaser]

check the vent on the fuel tank

[ceb]

This may sound ridiculous, but I've done it before. Make sure that the arrow on the primer bulb is pointed in the right direction. Also, does the primer bulb get good and tight? If the hose is on backwards, the bulb will just collapse.

[crappiencali]

I would go with either a diagrapm problem, a primer bulb. But it could be a coil pack or a winding. But like IBNFSHN said first I would check the primer bulb and then go from there. When you find out what the problem was let me know. I'm a heavy equipment mechanic and like to hear what the problems were on engines. Just incase I run into that problem in the. Plus I want to be a boat mechanic when I retire from the military. They make great money.

[Matt Smith]

I'm thinking it's a electrical problem. If your motor had coils, that would be the first thing I'd check. Since it doesn't, then I don't know. It's probably time to take it to a different mechanic.

[ShilohRed]

Next trip out when starting to give it gas. Hit the choke and see if that make it jump up on plane.
Pete

[crappie_mad_man]

sounds like a coil problem to me the engine will run good till the coil(s) heat up then they start breaking down had the same problem with mine changed the coils and it was fixed

[fishman247]

i had a 60hp merc that did the same thing....after endless trips to thje shop i gave up and bought a rebuilt 70hp merc.....it did the same thing.....on a full tank it ran good but anhy less than full it choked out....replaced bulb and lines....no help....ended up replacing the tank and now it runs great again....it was a small stress crack in the pickup tube inside the tank.........it's a shame i spent 900 bucks on the 70 when the 60 was a cheap fix

[FisherMike]

Here is where you will find your answer.
This guy is fantastic!

Do a search at the top of the page or sign up and ask the Doc.

http://www.themarinedoctor.com/cgi-bin/YaBB.pl