use of electric fuel pump?

[rbigg]

Got a 115hp Evinrude on an 18' c/c boat.

I'm wondering what the general thinking is about the desireability and advisability of using an inline electric fuel pump to push gas to the engine? Seems like an electric fuel pump would be way better than the bulb setup.

 

[F_R]

Re: use of electric fuel pump?

I fail to see why you think it would be an advantage. Keep it simple.

 

[Texasmark]

Re: use of electric fuel pump?

I attempted to do that on a I6 Mercury. Being as tall as they were, they were always thirsty to get started. I installed one as you mention. Forget now what problem I couldn't solve, but it wound up not working. May have been fuel dribbling out of the carbs when the engine was tilted; too much pressure for the float valve to seal off, or something like that; even with a regulator.

Since the electric was electric, it had a constant pressure on the carbs regardless of the rpm's whereas with the engine driven fuel pump, it pumped harder as you needed more fuel; worked much better.

The engine was only a couple of years old when I tried it so it wasn't that I needed to redo my carbs.

Or it may have been that once I got the pressure low enough to satisfy idle conditions, I didn't have adequate flow for WOT operation.

I solved my problem by eliminating some of the rising-falling, twisting-turning of the fuel line.

HTH

Mark

 

[Dhadley]

Re: use of electric fuel pump?

We've installed an electric pump on many boats. Some were just used to prime the system. V8 outboards came with an electric primer pump. Most all race boats have electric pumps. It'll work on your 115 but it's really not needed and a bit of an over kill as the primary pump. As a primer, it's not a bad idea.

 

[clint]

use of electric fuel pump?

I agree with the Lieutenant Commander, keep it simple. He is right about the starting. All of these outboards are finicky when first started up. I dont care what kind of outboard it is. I know my 140 evinrude starts different every time till the fuel pump and fuel flow has the engine pressure. As long as the primer bulb is pumped up stiff and with a little choking and idle up thats as simple for starting and operating as I want it to be. I would think also the constant pressure of fuel pushing to the carbs and the extra pressure at the hoses clamps could be damaging or dangerous if there was a leak during operation. The simple fuel pump operation that has been implimented by Evinrude runs on the pressure of performance from engine by pressure when the throttle of the operator calls for it. Keep it simple or face more complications.
Clint 8)

 

[Silvertip]

Re: use of electric fuel pump?

Electric pumps used on I/O's and inboards generally have electric fuel pumps wired through the oil pressure switch so anytime the engine quits or loses oil pressure the pump also shuts off. Without some sort of shut off protection (other than turning the key off) you risk pumping fuel on a fire. A broken fuel line, leaky fitting, etc. can result in fuel continuing to pump on a stalled engine. There is no easy way to shut the pump off automatically on a two stroke.