Low Pressure Fuel Pump REBUILD (Mercury EFI Outboard)

[@davidc7406]

I have the 125 mariner I rebuilt my fuel pump a few years ago and I used both black rubber and plastic check valves and it’s running fine still.

[@PrestigeWorldwideFishing]

Ok good to hear! I figured I would be fine but felt I needed to put that in there. Thanks for the info. 🤝

[@matt98eclipse]

Hey buddy by chance did this fix your issue?? I’m having same issue. I’ve tried replacing so many parts and cannot figure it out! I have same motor just a 200hp! Sucks not being about to get out and fish!!

[@PrestigeWorldwideFishing]

Hey man. I did fix the issue but went in circles so not exactly sure what did it. I replaced low pressure fuel pump, problem still happened. Replaced high pressure fuel pump and it stopped happening the first time out. Went out again and nearly didn’t make it back to the ramp because boat wouldn’t start. Got it home tried to start in the yard with muffs on and nothing. Pulled off my Amazon low pressure fuel pump and replaced it with the rebuilt fuel pump. Fired right up and I ran it hard on the lake with no issues so far. What have you tried? Maybe I can help

[@matt98eclipse]

@@PrestigeWorldwideFishing well that’s good to here! Hopefully it stays good for you. So…. Heck idk where to even start. Basically right now I can’t get on plane. Starts up and idles just fine! Revs up in neutral just fine. But try to get on plane it just falls on it’s face big time!! I’ve tried so many different things and can’t figure it out.

[@PrestigeWorldwideFishing]

Does it bog down or just won’t rev the motor high enough to get on plain? Might be your stator. It basically helps switch your low rpms to high rpms. If it can get to high it obviously won’t get up on pad. Hopefully it isn’t simulating a fuel issue like mine was and it is actually ECU.

[@matt98eclipse]

@@PrestigeWorldwideFishing so it revs up in neutral ok. Have noticed it doesn’t rev up as quickly like it use too. When trying to get on plane it has no power. Also noticed it’s running a lot richer then it use too. I’ve replaced low pressure,high pressure fuel pumps, injectors removed and cleaned/flow tested. Checked base fuel pressure at idle and wot trying to get on plane. It’s right at 37psi. So all the fuel systems checks out good. I’ve also already replaced with brand new cdi stator,trigger,switch boxs and regulators!! Had the ecu tested and said it was bad by brucata they said it was bad so I bought another one that’s been tested and known good by a shop…. I’ve spent so much money and time trying to figure out what’s going on with this dam motor. I’m about to give up! 😞

[@PrestigeWorldwideFishing]

@matt98eclipse Dang dude, I’m sorry. So it is the ECU? Did you buy a used/rebuilt ECU from a shop or new ACU from Brucato? If you bought rebuilt ECU, even if it was working it won’t last. Even if the part was soddered back together other parts can fail quickly. That is why I bought new from Brucato even though it cost me $1500

[@joemckillop3766]

Interesting … do you think this could be causing similar issue on 225 EFI? Basically motor runs great other than when shifting from neutral into gear - makes it tough to dock lol

[@PrestigeWorldwideFishing]

Possibly, could be a number of things though. Does your fuel bulb pump up easily and keep fuel in it or does it empty?

[@joemckillop3766]

It typically emptys I think

[@PrestigeWorldwideFishing]

Might be your low pressure pump then. My motor would actually die and my bulb would be completely empty. Couldn’t get motor to start until I pumped it up again. It would run fine for quite awhile and to it again.

[@jackmitchell123]

same issue on my motor did you solve it? i have same 225efi, great runner doesnt love to idle once warm. im looking at TPS next.

[@joemckillop3766]

Changed tps and never stalls anymore. Now I’m bogging down at 4k rpms. Think I have a fouled spark plug. Always something …

[@Boaters_hub]

That little plastic piece of shit that locks those check valves in is bullshit. Mine went fucking flying across the driveway and ill NEVER find it again. Now the check valve had a hole in the center and dont know wtf to do now 😡

[@PrestigeWorldwideFishing]

Yes I agree those things are super annoying. You can order another kit off Amazon pretty cheap… I know that doesn’t help your current situation though