15 hp Honda Outboard Problem

[Paul Housman]

Took our boat out last weekend. Noticed that after warming the engine up the engine worked fine until I got to the point where I had to go fairly slow or idle. The engine would quit. Worked well at half throttle or full but as soon as I slowed to an idle or real slow speed she stalled. I changed gas containers thinking I had bad gas. Didn't help. I think I have an Idea like possibly a fuel filter. Any other Ideas?

 

[Steve O.]

fuel vent?

Did you have the fuel breather vent open on the gas tank?

 

[Steve Dion]

check your oil too

I believe that they have a low oil pressure cut out too. If you haven't changed the oil do so and try it too. Does sound like fuel though.

 

[Ray Bowles]

Paul, I fixed exactly the same problem.

Our 10hp Honda did exactly the same thing. After warming up or extended running at half throttle when returned to idle or slow speed it would die. Shifting to neutral and then reverse would also cause it to die. The cause was the mixture of air/fuel in the carb.I bought the complete Honda factory manual awhile back and the correction is to adjust the a/f mixture screw while runnig at as slow a speed as possible in neutral. You will find two screws on the carb close together. The screw that has the spring on it and is conected to the linkage is the throttle stop screw and will raise the idle mechanically. The other screw that goes into the carb body proper is the a/f screw.(pilot screw) Adjust it for highest rpm possible before adjusting the throttle stop screw. Good luck, Ray

 

[L. May]

Honda issue - age!!!

Just went through an exhaustive (no pun intended) effort to fix the same problem you described. This was a 10 hp model that was about 10 years old and always flushed with FW after use. Found that there was an exhaust leak thru a portion of the housing (below the engine) that permitted exhaust fumes to be pulled back in and messed up the fuel/air mixture. Engine would run great with the cover off. Finally used epoxy to fill the eroded area, re-assembled the engine and runs like new.BTW... the Honda repair sources didn't figure this out!Good luck.

 

[Robert W. Bonney]

Another possibility

My neighbor is experiencing the exact same problem with his Honda outboard. After checking all of the same problems that everyone else has mentioned, his problem persisted. He finally took the engine to a Honda mechanic who pointed out that the "idler tube" was partially clogged with fuel deposits. A quick shot of carburater cleaner and a fuel additive solved his problem. I think the owner's manual will idenify the idle tube on your particular model. Hope this helps.