Update on my electric fuel pump installation.

[Texasmark]

Thought I'd get the boat out of the shed and run it up since it's been about 3 months since I was out with it. Set the engine vertical, hooked up the water, turned the key to ON. Could hear the fuel pump running, went back and felt the bulb and it had pumped it up nice and firm. Went back to the console, set the throttle to about 1/3 open, pressed the fuel enrichment function for about 5 seconds, rolled the key over to start, about 3 revs and this usually hard to start first thing, like my last Merc. lit right off and was ready to work. My my. What a difference.

 

[Chris1956]

OK, electric fuel pumps work well. How did you wire it in safely? If the fuel line breaks and the engine stalls, does it continue to pump and fill your bilge with gasoline?

 

[Texasmark]

OK, electric fuel pumps work well. How did you wire it in safely? If the fuel line breaks and the engine stalls, does it continue to pump and fill your bilge with gasoline?

Yes its a flow through. Yes I fused it.....actually the fuse makes a nice, easily accessed on-off switch for maintenance actions when I don't want it running. Yes the engine system wasn't touched.

 

[Chris1956]

So you need to remember to turn it off, if the fuel line leaks and the engine stalls? If so, that is a safety issue. Consider that you if hit something, the fuel line breaks and you are too dazed to turn off the fuel pump at the switch. Not unlikely in a collision scenario.

if you have a 4 cycle engine, you can run a relay to power the fuel pump off the oil pressure switch. it may have enough power (from the gauge circuit) to power the pump directly. You would also need to supply power to the fuel pump when cranking the engine.

On a 2 cycle motor, you may be able to install a relay on the AC side of the voltage regulator. it would need a diode to convert to DC, to power the relay primary winging. The relay, when energized, can draw power from the battery to power the fuel pump. When the engine stalls, the VR will stop making power and the fuel pump will shut off.

 

[flyingscott]

What have you done to that motor? Wow

 

[sam am I]

For 2 cycle, could also get a 3 or so PSI pressure switch and use the engine's water pressure to energize a relay that powers the fuel pump.

When cranking, if water pressure isn't high enough to trip the relay on, could have a momentary push button "prime" switch on the dash that temporally bypasses the relay to manually run the pump just when cranking. Once the engine starts, you let up on the switch because the water pressure would be sufficient and the relay now goes back to operating the fuel pump.......

Engine shuts off (or stalls), water pressure drops to zero, relay turns off, fuel pump shuts off. Same gig as the oil pressure setups on 4 cycles.

 

[Chris1956]

Most OB water pressure gauges are mechanical, at least those I have seen. They cannot power anything.

 

[flyingscott]

I am sorry why should we not be finding out what is wrong with the motor. I have worked on probably 50 of the 2+2 motors and have never had to add an electric fuel pump to make it start correctly.

 

[sam am I]

For 2 cycle, could also get a 3 or so PSI pressure switch

Most OB water pressure gauges are mechanical, at least those I have seen. They cannot power anything.

"Pressure gauge"?? No, get a pressure SWITCH...

Perhaps a picture.....and a link

 

[Texasmark]

What have you done to that motor? Wow

I fed it some fuel when it wanted it most...after sitting 3 months. If you use them every day, no big deal, they kick right off but sitting, things dry out.....at least mine do.
I got this idea that maybe I needed a water separator pre fuel filter since I have a 24 gallon tank and want to keep it 3/8-1/2 full so a lot of fuel just sits even though I use Mercury #1 fuel treatment ...... so I installed such and found that slow speeds/idling, startups moving from fishing spots to another, didn't respond like they used to and I just figured that my fuel pump (with OH kit less than a year old and seldom used) wasn't sucking hard enough at low speeds to overcome the new resistance in the fuel line. I didn't expect the performance improvement that I got out of the deal.....but I'll take it.

 

[flyingscott]

To anyone reading this post DON'T DO THIS!!! This set up is a huge safety issue. This is a potential fire hazard among other things. Use your common sense people, Not all info on the internet is worth following!!!!!

 

[marrisy]

Just fit a lpg energiser, when you first turn on the key, they power up for a few seconds to.prime the system, then when they don't get a signal from the ignition, switch off. . weren't expensive.