12 volt fuel pump for my 1989.125 Force outboard

[Stachi]

heya all ,...I recently bought an old school 12 volt fuel pump from an auto parts store..$42.00 , so I could remove the fuel that has been in the tank of the boat pictured below since 1997, and not spit varnish for the rest of the day...(siphoning it the old school way)...it worked like a champ...my outboard has two carburetors,... any reason I can't use it to feed the engine? I ask because of all I have read about ethanol , and older Force outboard fuel pumps not getting along well with ethanol...... the electirc pump is paid for already and I can either wire it with a fuse to the key on position, or a fused auxilliary switch that is at present not employed on my helm...eliminating the primer bulb would be a plus as well..Thanks in advance brothers....

 

[a70eliminator]

Re: 12 volt fuel pump for my 1989.125 Force outboard

The output pressure of the electric fuel pump seems like it would screw up the operation of the floats. I don't know just sounds scary to me, I/O's I've heard of being converted ok, just havent heard too much about outboard conversions.

 

[tx1961whaler]

Re: 12 volt fuel pump for my 1989.125 Force outboard

The problem is shutting off the electric pump automatically if the engine stalls by accident. No good way to do it on a non-computer controlled 2 stroke engine. Four-strokes get wired to the oil pressure sensor.

 

[Stachi]

Re: 12 volt fuel pump for my 1989.125 Force outboard

well , they were originally designed to feed carbureted engines...with float valves... they shut off at a preset pressure...they worked wonders on the 1960's era doghouse engined work vans that would vapor lock...just wondered if anyone had any actual experience with them on a boat

 

[Stachi]

Re: 12 volt fuel pump for my 1989.125 Force outboard

The problem is shutting off the electric pump automatically if the engine stalls by accident. No good way to do it on a non-computer controlled 2 stroke engine. Four-strokes get wired to the oil pressure sensor.

if the engine stalls, the back pressure to the pump from the float valve , is what shuts it off...thats how they work

 

[Stachi]

Re: 12 volt fuel pump for my 1989.125 Force outboard

if the engine stalls, the back pressure to the pump from the float valve , is what shuts it off...thats how they work

this is not a high pressure pump as are used in fuel injected engines (35 psi minimum)...this is a volume pump by design...it was designed for carburetors , hence the back pressure shut off... you turn the key , listen for it to chug for a second or two , wait for it to stop , and then choke and crank the engine.....does not sit in the tank , can be mounted anywhere you like (fuel line barbs at each port)...it only operates when the pressure drops ( the float valve opening)

 

[a70eliminator]

Re: 12 volt fuel pump for my 1989.125 Force outboard

I understand that, I guess if you knew the pressure of the outboards fuel pump and the electric pump, as long as they matched, but the difference between 1lb and 8 lbs could cause the needle to lift off it's seat.

 

[Stachi]

Re: 12 volt fuel pump for my 1989.125 Force outboard

I understand that, I guess if you knew the pressure of the outboards fuel pump and the electric pump, as long as they matched, but the difference between 1lb and 8 lbs could cause the needle to lift off it's seat.

I agree,...it would be a good idea to find the values of the float valve...I guess pump volume will tell the story, mechanical vs. electric pump, if the numbers match , I may be ok....I have a feeling that a leak in a hose or connection could become a VERY hazardous condition,.... I don't need to install it as I know of right now...just exploring the idea...all input is appreciated...

 

[tx1961whaler]

Re: 12 volt fuel pump for my 1989.125 Force outboard

this is not a high pressure pump as are used in fuel injected engines (35 psi minimum)...this is a volume pump by design...it was designed for carburetors , hence the back pressure shut off... you turn the key , listen for it to chug for a second or two , wait for it to stop , and then choke and crank the engine.....does not sit in the tank , can be mounted anywhere you like (fuel line barbs at each port)...it only operates when the pressure drops ( the float valve opening)

Go ahead. Sounds like it will work fine for normal operation. It's the abnormal operation that you have to watch out for. If the float sticks and the engine stalls, the pump will not shut off and you'll be pumping gas into into the cowl. Same deal with a split fuel line.

 

[Silvertip]

Re: 12 volt fuel pump for my 1989.125 Force outboard

Not only will it pump fuel into the cowl, but it may pump fuel into the engine. Hit the key to start it and you may have ---- well ---- does "kaboom" mean anything to you. You must have an automatic shut off should the engine stall (yes - with a defective carb needle and seat or any other reason). This will work -- until the day when you actually experience the above issue. You are indeed tempting fate.

 

[Stachi]

Re: 12 volt fuel pump for my 1989.125 Force outboard

Go ahead. Sounds like it will work fine for normal operation. It's the abnormal operation that you have to watch out for. If the float sticks and the engine stalls, the pump will not shut off and you'll be pumping gas into into the cowl. Same deal with a split fuel line.

I am currently restoring my boat and engine..no system goes without a full refit ...including new fuel lines... safety first....also,I am an ASE Certified Automobile Mechanic by trade so I know a thing or two, about a thing or two...lol... I'm more concerned with a float failing before a float valve breaks...never seen one break...hang up , yes...float failing because it leaks.. yes...I am going to look for a limiting valve...like they have developed for washing machines... it is located at the hot or cold water supply connection in new washing machine hoses sold today.....if the hose breaks beyond the valve, the volume of water through it closes the valve....they developed it when washer/dryers were installed on the second floor of houses...to limit the damage to the insurers when a supply hose leaks...... if I can find it for this application, it will be installed at the pump.If it is not available , maybe I will scrap the idea...good input from all and Thank You.
If anyone knows of a valve for this application , please let me know...Thanks all

 

[NYBo]

Re: 12 volt fuel pump for my 1989.125 Force outboard

Sounds like a solution in search of a problem to me. New replacement fuel pump diaphragms should be fine with E10.

 

[Stachi]

Re: 12 volt fuel pump for my 1989.125 Force outboard

lol... good point...the pump is paid for , if I can find the valve and be safe......

 

[kenmyfam]

Re: 12 volt fuel pump for my 1989.125 Force outboard

Just my 2 cents....but.......Don't Do It !!!!
Scarey stuff. Stick with what the motor was designed for.

 

[Netjunky]

Re: 12 volt fuel pump for my 1989.125 Force outboard

Off topic but you said your doing some restoration work to your boat. As we have the same model of Bayliner, I would be interested in seeing some pictures. If you need any measurements from mine let me know.

 

[cambosoup99]

Re: 12 volt fuel pump for my 1989.125 Force outboard

I was thinking about doing this also. to address the problem if the motor stalls, I came up with an idea to wire in a relay to allow power to the fuel pump when running. if stalled no power to the relay and fuel pump shuts off. make sense.

to do that i would get power from the regulator dc side (since regulator only has power when engine is running) to activate the relay which turn routes battery power to the fuel pump; or disconnects power if the motor isn't running.

You could also wire in a manual shut off switch/disconnect for added safety at the helm.

sketch below

 

[jerryjerry05]

Re: 12 volt fuel pump for my 1989.125 Force outboard

First:WAY too much pressure!!!! Second it probably isin't a CoastGuard approved pump.They cost about $85 and are for anything but an outboard.
If you got checked:BIG TICKET!!!
Like some others said no way to automatically shut it off.
If your gonna carry any passengers make sure you tell them your driving around in a BOMB!!!! And you just might kill them and their family.J

 

[my1stboat1]

Re: 12 volt fuel pump for my 1989.125 Force outboard

i say this world wasnt built on not tring something new... People will always say dont dont dont... But the guy who did is making money over something that everyone was thinking off.. Try it out see how it works and hell if it doesnt take it off... if it does patent the **** and sit with a smile... Just remember some guy at some time decided to put baby umbrellas in alcoholic drinks that guys a millionaire

 

[murrayhooper]

Re: 12 volt fuel pump for my 1989.125 Force outboard

i say this world wasnt built on not tring something new... People will always say dont dont dont... But the guy who did is making money over something that everyone was thinking off.. Try it out see how it works and hell if it doesnt take it off... if it does patent the **** and sit with a smile... Just remember some guy at some time decided to put baby umbrellas in alcoholic drinks that guys a millionaire

I had nothing but trouble with my johnson fuel pump so i fitted a 12 volt inline pump that ran at 4 lbs pessure and cured my problem completely

 

[Jiggz]

Re: 12 volt fuel pump for my 1989.125 Force outboard

This is not the first time an electric fuel pump (EFP) has been discussed on this forum. Although, it generated a number of cautions and warnings, so far no "kaboom" has been reported, at least none that I am aware of. However, those who tried eventually went back to the original fuel pump design and abandoned their electric fuel pump quest. Why? No common reason was given. The electrical safety diagram suggested by "CamboSoup" looks promising as long as the operator shuts off the ignition key when the engine stalls to stop the EFP, which means when engine stalls, it doesn't really stop the EFP instead the relay switches back the source of power to the battery through the ignition switch. Unless, there is a separate cut off switch for the battery power which should be turned off manually after the engine started.

However, if the EFP has an auto back pressure cut off switch, this means the ignition or a manual safety switch is only a back up thus providing more safety. So the other concern with the use of EFP is the higher output pressure compare to the 2~3 PSI provided by the original fuel pump. But even this can be resolved with the use of orifice or pressure reducing valves. Or even better is to pipe in an additional return line back to the fuel tank. So the final question is, how reliable is an EFP compare to the original fuel pump design? What will be a back up pump just in case it goes kaput in the middle of nowhere? Where will you locate the EFP, inside the cowling? On top of the tank? somewhere it is readily accessible, sealed? enclosed? protected? I believe it can be done as long as these primary concerns are addressed: Safely stopping the EFP when engine stalls; reducing output pressure; reliability of pump; environmental concerns in case of fuel leaks and location of pump (this is a concern if the pump leaks)