Still having fuel problem

[billybass]

If I run at 4000rmp, can run all day with no issues. Once I get up to about 4800rpm and above the motor will just die out after a few miles. After I pump all the backwash out of the bilge , the motor starts right back up.

I've replaced all the fuel filters, cleaned the O2 sensor, and changed the primer bulb. Does anyone have any recommendations before I spend the money on a new fuel pump? Doesn't seem like the pump when it allows me to run all day at the lower rpms?

Thank you all, Bill

[briansgi]

I assume it does this on both fuel tanks? Sounds like a fuel venting issue. I know it's not the same but I had a Yamaha waverunner, brand new, that would run all day long until you went to full throttle, then it would die. The fuel vent line was partially closed.

[21XDC]

You just need new fuel pump "Diaphrams"... Boats.net sells them cheap and you can install them with ease.

[21XDC]

I got the IM...

I sent/e-mail the service manual for my motor to help you... Let me know if you got it and helps you any.

[billybass]

I will Mike, thank you sir.

[headhigh]

Bill, before you replace anything on the fuel pumps I'd check your fuel tank vents and your primer bulb. I was having the same issue with my boat when running off the port fuel tank. I noticed when I ran it at higher RPM's the primer bulb would start to flatten out. Turned out the port tank vent line was pinched shut and was creating a vaccum in the tank. Took the crimp out of the vent line and I've had no problems since.

[Davew]

Also check your fuel lines in addition to the primer ball... I had a similar problem a while back; chnages the ball, fuel pump diaphram, etc, etc. with no luck. put it in the shop and all it was was deteriorated fuel lines. The mechanic gave me an envelope that had a bunch of trash that looked like a yellow silicone sealant. he said something about the newer fuels attacking the fuel lines which caused them to break down. Good luck.

[billybass]

Wow guys, thanks for all the advice!