Honda BF40 Issues

[Perchjerker19]

I posted on MarineEngine also, but thought someone here could give me guidance with this issue: 2012 BF40, Fuel Injected, owned since new.

The engine has been stalling when trying to give it throttle. It happens only after the engine has warmed up. It began cutting out last summer only after 4000RPM. During the winter it would not cut out at all, or only sporadically. Now it has gotten worse to where as soon as it warms up, you cannot give it any throttle before it stalls. It starts and idles. It idles a little rough. I have done the following to try to remedy the issue:

1. Changed spark plugs, no difference
2. Changed fuel line, gas cap, and fuel filter in portable gas tank, no difference
3. Changed water pump and thermostat, no difference
4. Opened up water separator, clean and no signs of water
5. Opened up fuel strainer on the vapor separator, clean with no signs of gunk

Any advice would be greatly appreciated. It's now out of warranty so I'm trying to avoid taking it to a shop.

[Hickory Legend]

Coils??

[Perchjerker19]

Took to dealer. Fuel pump insulator in the vst had expanded causing fuel starvation. Cause was from ethanol. Honda warranties the fix even though it was 11 months outside warranty.

[Hickory Legend]

[ROADRUNNER]

Did you change the primer bulb? If not change it. Possibly coil related or electrical, as the engine heats up the wire expands/moves and the electrical flow is broken. It happened on a car I had once. We found it by running the engine in dark and you could see the spark jump to the block. It sounds crazy but it is easy to check.