Starts then stops

[Fred1diver]

Hello all, getting ready to winterize the boat, but the last few times I used it it died after a few minutes after starting her up, the idle seems to go up and down, not sure what could be the cause or how to fix it for next season.
Any leads would be good
Thanks I’m advance
Fred

[Al Schober]

Sounds like fuel starvation. The engine will run for a few minutes with just the fuel in the float bowl.
I recommend adding a small pressure gauge to the carb inlet. This would determine if fuel is getting to the carb and determine the next course of action.

[Fred1diver]

Ok, I will do that next spring as the motor is winterized at the moment
Will also change the water separator filter and fuel filter at the same time

[sastanley]

fred, Where are the filters with respect to the carb and pump? I had a water separator close to the tank, and the inline filter, like the one Moyer sells, I had in the loop between the fuel pump and the carb, along with the pressure gauge Al recommends. The pressure gauge was the last item in the fuel line before the carb inlet. It does not have to be fancy. I used the Mr. Gasket #1561, but anything similar would work, as these engines are operating in the +/- 3 PSI range. The gauge will help determine if you are getting adequate fuel pressure at the carb inlet. I had water in the fuel some years back (faulty o-ring on the deck fill) and the water separator did its job as the gauge would go to zero as the engine died from fuel starvation due to the filter being full of water.