1997 Mercury 225 EFI

[h^10]

Hello ALL,

I have a 1997 Mercury 225 EFI that has been a great motor, however, I have started to have what I believe to be fuel issues. The motor idles okay as long as its a "light" idle. If I idle with some throttle it begins to seem like it starves of gas. I can have a buddy pump the bulb for a little while then I can get on pad for around 30-45 seconds then the motors starves for gas again but never shuts off completely. Does anyone have any guesses as to what this could be? I replaced the primer bulb and it is still having this issue. Have rebuilt the mechanical fuel pump as well. My guess would be electrical fuel pump or maybe throttle body?? Now I did have a loose negative on my electrical fuel pump and have not been able to take it out after tightening it up. I just want to get some ideas before I order parts. Thanks

SER#: 0G507999

[Rip Bass]

Have you ever replaced the fuel lines from the tank/s to the engine? I would start there. Old lines can collapse inside and cause fuel starvation.

[h^10]

I’m sorry I failed to mention that it runs perfect on muffs. Only has this issue whenever it’s in the water under a load. Would bad fuel lines still cause the issue under a load??

[jerzia]

I’m sorry I failed to mention that it runs perfect on muffs. Only has this issue whenever it’s in the water under a load. Would bad fuel lines still cause the issue under a load??

Besides the loose connection you found, bad fuel lines and primer bulb can cause all sorts of problems. Rip Bass is correct, start there, it's one of the most inexpensive fixes you can try and often solves some crazy issues.

[EuropeanAM]

See the FAQ Section- Specifically the "Fuel Lines and Performance Problems" link. Follow it PRECISELY.

[digthemup]

See the FAQ Section- Specifically the "Fuel Lines and Performance Problems" link. Follow it PRECISELY.

^^^^^^^^