F150 Yamaha keeps fouling plugs

[valentic07]

so we had some fuel issues with the boat be we are running it now with a fresh tank in a separate container yet after a few WOT runs it keeps fouling out plugs. or could it be bad gas that keeps fouling them?

 

[BaileysBoat]

Re: F150 Yamaha keeps fouling plugs

What do you have for filters? Did you take a fuel sample from the VST?

What max rpm are you getting? Is the engine making oil? Did you change the oil?

 

[Graham Williams]

Re: F150 Yamaha keeps fouling plugs

so we had some fuel issues with the boat be we are running it now with a fresh tank in a separate container yet after a few WOT runs it keeps fouling out plugs. or could it be bad gas that keeps fouling them?

Check you manual to be sure you are using the correct temperature plugs.

 

[sdsaw]

Re: F150 Yamaha keeps fouling plugs

I'd check the thermostat to make sure it is not stuck open.
If it is stuck open, your ECM will think that the motor is cold and will give you an overly rich fuel mixture.
JMO