Sputtering problem

[dogwood2]

1999 5.0 mercury in/outboard motor for a Chaparall, having a problem and need some help. Cranks fine, idle may vary, runs good to 3000 steady rpms, then starts surging and sputtering. If give rest of gas, seems like starving for gas and just sputters. We are new boaters and just wanted to see if anyone had a suggestion. We thought gas may have had some water or ethanol. Thanks. jc

 

[a70eliminator]

Re: Sputtering problem

10 yr old boat when is the last time it had a tune up? Carefully remove the fuel seperator and pour it contents into a clear jar and that will tell you if there is water in the fuel.

 

[TilliamWe]

Re: Sputtering problem

Ethanol is not the problem. And people that tell you it is, are just hyping.

You could have amirad of problems. But fuel delivery seems to be the most obvious. After checking/replacing the water/fuel separator, then you need to see if it's actually getting fuel to the carb. There is a yellow tube that runs from your fuel pump to the carburetor. if the fuel pump has failed internally, this tube will have gas in it, and it's not supposed to.
Another fuel line clog issue takes place at the top of the fuel tank, where the pick up tube comes out. There is a little check valve in there that keeps the gas from draining out of the fuel lines on the engine and back into the tank. Debris can make that check ball get stuck.

Good luck with your Chaparral.