Dead Head electric pumps are a flawed design from the get go. The pump can overheat with just the key on if there is no oil pressure switch safety. Electric pumps work well with return style fuel logs or regulators as they are able to keep pumping cool fuel. I would not use them otherwise.

Soumds like you would have gen 4 blocks in a 78. Go with mechanical pumps and relax.

I think you all are reading more into it than what it simply is, and that is mount the pump no higher than a couple inches at the most higher than the pickup coming out of the tank, at near empty you are still pulling fuel 12 to 18 inches up.

I would not be so adamant about trying this first if the cure I was suggested had not worked so clearly after it was completed by me after beating my head against the wall for 6 months and the professional generator installer suggesting the tank pickup was bad.

The generator was mounted in a large sailboat I was captaining by professional installers who fit 100 pounds of chit in a 10 pound bag very impressively. But after going thru 3 pumps they blamed the fuel pickups in the tank and walked so I took the problem over.

Thank god for friends in hi places who are older and been around the block a few times and has been building and running airboats for 30 years.

Almost was ready to cut the bunks up and remove the tanks before he informed me of this technicality with fuel pumps.

But if you have the provisions to mount mechanical diaphragm pumps as wobble and SB on here stated go for it. Cheap and very functional and reliable.

My buddy is running a high volume Holley mechanical pump on a 650hp Dart based 427 SBC. He never has fuel starvation and the car is a rocket ship!!

I've got gen VI 502's in it, no way to use a mechanical pump, and it's wired with oil pressure switches so the pump won't turn on until the engine is turning over.

since making this post, brand new pump # 2 has died. Pulled it apart because I was pissed that a fuel pump with 5 min of run time could die. The pump head itself looked fine, and when I hooked it to a direct 12v source, nothing. Hit it a few times to see if it would start spinning, still nothing. separated the pump from the motor and had to spin the shaft from the motor to get it turning. Let it run for about 30 sec, and turned it on and off 3 times. Set it down on my bench and answered a phone call. came back to it about 5 min later and tried again; it was already seized again. This time hitting it with a screw driver got it going.

I don't think being above the tank is hurting it, as soon as the good pump gets power it's almost instantly showing fuel pressure at the carb. The pumps are also mounted a little lower than the fuel filter/water separator.


I've checked the wiring, and sitting with the key off there is 0v going to the pump, key on engine off, 0v, key on engine cranking was 11v and once the engine started the reading was 13v

I'm hoping i just got a bad batch of carter pumps. The replacement on my port motor is still working after sitting a week and about 6 min of run time, which is more than the pump before it. I just don't see how a total of 5 min runtime (no longer than 1 min consecutive) with fuel pumping through it could kill a good fuel pump if it wasn't already flawed.

Sorry to thread jack, but I'll post my question here.

I'm sorting out a new-to-me 502/502hp 850 carb package, and seem to be missing about ~100hp. I'm running a Holley Red electric fuel pump with 67gph @7psi or 98gph free flow. That should be adequate for this package, yes?

Thanks!

I wouldnt use that pump. Borderline imo. Plus they are known to fail. If you must use an electric pump, the mallory 140GPH pump/regulator combo is pretty decent pump for the money. .

Sounds like the brushes in the pump are getting corrosion on them or something. Why cant you use the sea pump/mechanical pump setup mercury uses?

I actually hate the noisy bugger. The new motor has a provision for a mechanical pump so I'm going to sort that out.

Thanks!

no way to use mechanical pump, gen VI blocks do not have a spot for a mechanical pump. I think I finally figured it out, and at the same time I said F**k the carter pumps and exchanged them for the holley blue pumps and pressure regulators.

The issue with the carter is that they want the gas flowing THROUGH the motor itself for cooling. 4 out of 5 pumps I went through weren't letting the gas go through the pump head and into the electric motor, so after running dry for a few minutes, they seized once turned off. ****ty design, and I would never want gas flowing through the electric motor . The holley ones don't want any gas to enter the motor so i think I should be fine now. FedEx tracking says they will be here tomorrow, so hopefully I'll be able to take the boat for its first ride this weekend!