Mechanical to electric fuel pump

[Sheehandler24]

I’ve got an old a$$ 140 (1975) with priming issues and I’m looking for a solution. It idles great and revs up to just shy of 2000 rpm then bogs to the point where if I push it any further it’ll stall. It’s got an inline filter and it takes forever for it to fill with fuel but once it does the boat takes off no problem. Found some low pressure inline electric pumps for cheap. Just wondering if that’d do the trick or if there’s something else I should look at with the rest of the injection first?

 

[Scott Danforth]

the mechanical pump is 1000000000 times better than any electric pump.

look for the problem. most likely the anti-siphon valve, etc. your in-line see-thru filter is not legal on a boat. get a proper marine fuel filter head with a water-separating fuel filter element.

additionally, the cheap electric pumps are junk.

 

[Lou C]

Agreed I would not replace a mechanical fuel pump with an electric for that reason; it may not solve your problem assuming the mechanical pump itself is good. The last mechanical pump I replaced was 30 years old! In fact if I can get a good reman 4.3 when the time comes I plan to stick with a pre-Vortec engine just to be able to keep using a mechanical pump! Cheaper & more reliable!

 

[Sheehandler24]

Interesting. I’ve heard the opposite from car people. I switched my old diesel truck to a cheap electric pump that’s been on for like ten years. Made a huge difference. But I was just spit balling! How about just a regular old primer bulb? I went through the system last night and everything seems to be fine. I will be getting a water fuel separator, just wanted to make sure my tank wasn’t full of demons first

 

[Scott Danforth]

most likely your anti-siphon valve isnt there, you have a minor leak and the fluid is running back to the tank.

No need for band-aids on a properly maintained fuel system

I long for the days of mechanical fuel pumps on cars. 30+ years and hundreds of thousands of miles vs the electric pumps craping out after 7-10 years

 

[Lou C]

Plus the safety cut off switch and wiring you need to have can cause trouble in a corrosion prone marine environment. Mechanical pumps have 2 less points of failure no wiring connections & no switch.
Everyone thinks EFI is the ultimate but I disagree it has many more potential failure points & expensive components Vs a carb.
Mechanical pump & cleaned & tuned carb is superior long term for old boats.

 

[Sheehandler24]

Well thanks guys! Where is this anti-siphon valve supposed to be? The fuel lines have all been replaced by the previous owner and I don’t see anything along them that looks like a valve. I’m assuming he neglected to put it back. Or is it up higher near the carb?

 

[Lou C]

The barb on the tank where the fuel line connects is where the anti siphon is usually located.

 

[Scott Danforth]

The barbed fitting IS usually the anti-siphon valve. They are usually stainless or aluminum

 

[Sheehandler24]

Oooooh yes I see it! I’ll have to see if I can get one at the auto parts place in town. Thanks fellas!

 

[Scott Danforth]

NAPA is the only place that MAY have it. Any marine store WILL have it

 

[Sheehandler24]

NAPA is the only place that MAY have it. Any marine store WILL have it

Good point, I’ll get the water fuel separator at the same time. I’d imagine they have universal ones of some sort

 

[smoothforce]

I used an electrical fuel pump when I installed a carbureted 5.7 Vortec on my cruiser. It worked just fine. Too bad the engine did not perform well due to prior owner improper installation of custom connecting rods. I took his word and did not inspected the engine internals. It would idle fine until the cows come home, but would try to seize when under load for longer than 30 minutes, so the boat could only be run at idle speed. In retrospective, the extra ponies were not worth all of the expense (intake manifold, fuel pump ect) and effort to set it all up. Much easier and safer to stick with the Gen 1 small block chevy, as I did afterwards.