Re: [OMC-Boats] Fuel Pump Woes

For what it's worth, I've been running an automotive fuel pump (I think
it's a Holley red) for as long as I've had the boat - it was installed by a
previous owner. The plumbing is tank, fuel shutoff valve, fuel filter,
pump, and then straight to the carb. It's wired into the key switch - it
comes on when the key is in the "Run" position (or "Accessory", which has
always annoyed me). I know you're supposed to use marine pumps only, but
the pump failing and leaking externally is pretty far down on my list of
concerns.

Just make sure your pump is designed for carbureted engines and rated for
the proper pressure (a few psi?). My engine has a "blanking plate" over
the spot where the original pump mounted - you could maybe leave the old
broken pump in place, but it might eventually overheat and seize without
fuel to cool it - I'm guessing the plates are pretty easy fo find.

My opinion for the "best practice" for wiring up electric fuel pumps on
non-computer-controlled engines is to put them through a switch that's
driven off the oil pressure sensor. So the pump only turns in two
circumstances - when there's oil pressure, or when the key is in the
"start" position. It's a cheap way to protect your engine in case you ever
lose oil pressure, and it avoids running the pump when the engine isn't
running. It might be tricky to wire that up though with the
grounded-when-there-is-no-oil-pressure switch that's used in these engines
- you'd need some clever setup with some resistors, a transistor, and a
relay... Er, or you could just buy the Sierra part:
   http://www.marineengine.com/parts/sierra_catalog/80240033.pdf
(OP22900 would work, I'm guessing, though maybe the 22891 would be a better
choice). This might require finding another spot to plug in an oil
pressure sensor though, or installing a T, so it might be complicated.

Ethan

On Mon, 31 May 2010, BLDFW wrote:

> Alas, on my maiden voyage of the 2010 summer season with my newly
> fabricated and installed side guides I never made it away from the boat
> ramp.  While I had a couple of successful runs late last year, this year
> the fuel pump crapped out before I could get her away from the ramp.  It
> would not pull from the full tank.
>
> Question.....
> I have a spare electric fuel pump I can use to bypass the old mechanical
> one.  I know someone will say it so I'm going to inquire.....What's the
> con of using it on my boat??  If I were to use it, is there a best
> practice method of hooking it up aside from the ignition key source?
>
> Thanks.
>
> -Bill
> Dallas, TX
> 1970 Evinrude Explorer - 155 Buick V6 - OMC Sterndrive
> http://www.photobucket.com/evinrude_explorer
>
>
> PS...the guides worked really really well when we floated it back onto
> the trailer.  Looking forward to doing it under power!
>
>

-- 
<a href="http://homepages.cae.wisc.edu/~brodskye/"> Ethan Brodsky </a>