Electronic fuel pump on Carb Motor

[nymack66]

I am sick and tired of the primer bulb and the excessive cranking at the ramp. I am going to install electronic fuel pump on my 87 Looper and remove the current mechanical pump.

I have decided to implement this with safety in mind first and foremost.
I have searched and educate myself on Scream and Fly's where the racers have done it various ways.
Arguments were plenty in regards to regulation and pressure etc, Holley vrs Carter pumps etc, regulator or not ....
I went with "Airtex E8337 MARINE FUEL PUMP ELECTRIC UNIVERSAL EXTERNAL IN LINE MARINE FUEL PUMP COAST GUARD APPROVED FREE FLOW 5psi-9psi 30gph 5/16 INLET OUTLET BRAND NEW FACTORY FRESH FOR CARBURETED 12 VOLT NOT FOR FUEL INJECTION"
from Ebay.
Regulator is

Red Billet Aluminum Fuel Pressure Regulator w/ Gauge

3-12 PSI Adjustable 2 Port

These high quality regulators are adjustable from 3-12 PSI. Has one 3/8" NPT inlet port and dual 3/8" NPT outlet ports, non return style.
Red anodized for great looks and corrosion resistance. Includes mounting bracket.
Universal design, these regulators work perfect for carburetor gas applications from street to high flow race engines.
Please see my sketch up of exactly what I am doing. I will post results after its tested for, lean,wot, starts etc.
I will check and verify all fuel lines and replace as necessary. The entire setup will be in the hatch area attached to the Transom on the inside skin, away from the elements.
I am not sure if any one here did to a carb motor and can share some experience on this ?

[RidgeRunner]

I ran a small electric pump on my airboat. It never failed in the 5 years I had it. No fuel filter or regulator necessary for the little pump. It was mounted to a piece of the steel cagework and made a thumping noise about 1/3 as loud as a Holley Red. LOL. Noise not being a concern.
Going full electric, should you have an electric source failure, you would be unable to make way and electric things have a limited lifespan. Offshore, that could be a problem.
What is the capacity of the charging system on that 140 Johnrude?

[THEFERMANATOR]

You don't need a regulator with that low pressure pump. The stock VRO pump will spike upwards of 9 PSI or so if you put a guage on one. One big word of caution is to watch your voltmeter. The 140 looper has a WEAK charging system to say the least. Mine only put out .3-.6 amps at an idle, and didn't ever reach 9 amps(rated output) until 6100RPM's(redline). At a 3800 RPM cruise it only put out 3.6-5.1 amps, so it never really kept up with many accesories, and I always had to put a charger on it when I got home. The early 9 amp charging systems were pretty sub par to say the least.

[phatdaddy]

ferm & ridge might know this, but why abandon the built-in fuel pump? i would let the electric prime the system and after about 3-5 minutes of running, shut it off and let the mech do its thing. this is what we do on our trenchers. they have v4 wisconsin engines and the fuel pump is not that reliable and a pia to get to, so when we have a problem, we just install a cheap elec inline and leave the existing in place.

i can always tell when my merc pump is getting weak, after about 15 - 20 minutes of trolling, it starts starving for fuel and i have to pump the ball up.

[spareparts]

your font is giving me a headache


you're putting it on a looper? Before you do that, make sure you have good fuel line, run a name brand primer bulb(Bomb, Yamaha, Merc) and see if you have an anti siphon valve in teh fuel tank outlet. You shouldn't have to have an electric fuel pump if everything else is in order. OMC offered an electric prime pump for a while

[phatdaddy]

didn't sea drives have them?

[nymack66]

Excellent feedback Guy's, I was indeed thinking on keeping the mechanical pump in line and wire in this new pump as an auxiliary pump to a "rocker switch" use only for cold starting and run her on the mechanical pump at WOT etc. With fuel flowing freely through the free flow pump and regulator.
My proactive concerns is restriction at WOT with the vacuum pull having to suck through a Pump/Primer Bulb/regulator/pump/filter/ etc.
With the mechanical pump connected I thinking it can boost the fuel pressure up out of tolerance for the Carbs....

Spare sorry about the fonts I did a few Cut & Paste from Ebay etc :) The cold starting at the ramp drives me crazy. Once the primer is primed and she started it starts at the bump of the key there after. Its clearly lack of fuel since I observe the primer goes very very soft before the hard starts.

[THEFERMANATOR]

The primer system on the OMC's requires you to pump the primer bulb up hard before you go to cold start it. The primer system uses the fuel pressure from the fuel pump to inject fuel behind the carbs, so if the fuel bowls are n't filled it will have to fill them before it can get enough pressure to push fuel through the primer system. Just be careful as alot of inline pumps require quite a bit of vacuum to pull fuel through them, and the V-4 doesn't have a fuel restriction sensor to tell you if there is to much restriction to the pump which can lead to a lean out situation. The extra fuel pump before the VRO pump will not lead to extra pressure as the VRO pump works off of the pressure going out of the pump. And I doubt you are, but your VRO will not work with the electric inline pump so you will have to premix.

[nymack66]

Thanks Ferm, My VRO is plugged I am currently running pre-mix

[nymack66]

Install the fuel pump, I notice it is not exceeding 2 PSI? I bypass the motor and use it to pump all the old fuel from the tank looks like STA-BIL did its job, some curd and water was noticeable however.
I replace the fuel filter also, I will fuel her up with fresh fuel 50:1, spray some sea foam carb cleaner directly into the open carbs and bump the key. Stay tune :)

Current configuration TANK>Fuel/Water Separator Filter>Fuel Pump>Regulator>Primer Bulb>Carbs