Heres the problem. I have a 17' runabout with a 2.5GM inboard/outboard 120hp mercruiser. The problem I have, the lobe on the cam that runs the mechanical pump is wore down, and now wont work the pump. So I took a Carter electric pump, that runs 6-9PSI 30GPH pump, hooked it up, and problem solved. Right? WRONG!!!!! The boat runs mint, idling. Mid throttle is ok, full throttle, it dies. I couldnt figure it out. Started messing around, found out, when I punch it, its cleaning the float bowl out, and starving for fuel. So heres the question. Will a 10- 14 PSI pump running 100GPH work, or am I gonna be in the same situatuation? I have no idea how to determine if the problem is the pressure or the GPH. I figure going from 6PSI to 10PSI isnt much, but going from 30GPH to 100GPH is. How do I determine which way to go? Thanks in advance for all the help!!!!!!!!!

Purcell

 

When you say FLOAT BOWL I think carburetor with a needle and seat. If that is the case I would worry about overpowering the needle with too much pressure. I would go for more GPH with a regulator in the line. Have you checked the fuel lines for any obstructions? (collapsed line, kinked line, plugged fuel filter, etc)

 

First off. You need a marine pump. IF your running an auto motive pump when marine patrol stops you your going to hate life, or worse yet, when your boat catches fire your gonna really hate life. there is a reason marine grade electronically components cost more. They are sealed to not cause sparks or to short out if they get wet.

Now for your problem

You need to first see what pressure the carb calls for. I would step up up the GPH, 10 is to little for the fuel demand the engine needs during hard acceleration. Just make sure the extra pressure wont hurt anything.

 

First off, I did take the necessary precautions for the pump emergency shut off, by running a T off the oil pressure gauge, so if the motor reads less than 5 LBS of pressure, it kills the pump. Same as electronic pumps came from factory.

Second, at idle, the carb runs 2-7PSI, and Full it runs between 18-30PSI.