Fuel pump was changed to electronic

[Jim Robbins]

I/O Mercruiser with 140 hp. GM 4 cyl. motor 1973(?) and the previous owner instaled an electronic fuel pump(removed the mech. fuel pump). A fuel line runs from the fuel tank to the electronic fuel pump then to the carb. Should I have a over flow/pressure line returning to the fuel tank? I need to learn more about this, if there is too much fuel pressure is there a chance fuel is forced into the oil? I will prob. have to go to a marine mach. to check out what's been done, and if it will work properly. Any and all advice is greatly appreciated, thank-you

 

[havasuboatman]

Re: Fuel pump was changed to electronic

No you don't need a bypass. So long as the fuel pump put in your boat is a low pressure pump. (4-7 psi) You should, however have an oil pressure cut off switch installed so the pump is only running when the motor is running.

 

[Silvertip]

Re: Fuel pump was changed to electronic

You'll also need a second circuit to bypass the oil pressure switch while cranking as the pump wouldn't run until oil pressure was built up. Without these safety features you have a potential for disaster.