Only when I go to the Ozarks !!!!!

Eng had a 6 valve 130 GPM pump with 1/2" lines from tank to carbs on it when it went lean. Suspect something got into the check valves inside the pump and it dropped the fuel press.

I'm running full roller 454's making ~500hp, but like I said before, it's not for capacity. The mech pump should have been 2x what the eng needed, but it went lean anyway.

it was in a race boat so it ran for an hour at a time at WOT and never had a problem. the electric was on a switch but was just there as a backup as you hate to lose a race because a pump failed with a lap to go. we never needed the electric pumps and they basically were just used to prime the system when the engines were changed. the electrics were Weldons so they could handle it just fine if needed.

I have some switches that trigger at 4PSI. If psi falls below 4psi, switch makes contact, triggers my alarm and LED on dash. I know what you're thinking of doing, to save your engines, and its a good idea, but I think you'll be fine with the right pump and lines, as long as your not running some crazy 1200-1500HP boosted engine.

Well, theres certain things you cant avoid. A piece of crud getting stuck in a needle and seat can do the same, no pump can fix that. Mercury used those 6 valve pumps on the 800SC, 900sc and 1000sc. How much power you making?

I originally was just going to install the low press switches, LEDs and alarm, then I decided to take it one step further. .Then came working out the details and this is what I came up with. With this set-up you can still stay out on the water running the elec and deal with the mech pump later.

I'm still having fuel press issues with these pumps as we speak. One min they are at 8.5 psi, next min they are at 4.5 psi. The pumps are 10 years old and I'll be ordering rebuild kits ASAP. That will probably resolve the unstable fuel press issue, but some insurance wouldn't hurt.

Ya after 10 years might be time for a kit. Also make sure no air leaks on inlet side of pump and lines. Been there

zz28zz - I can certainly understand your concerns. Back up was one reason I was considering going with a mech/elec combo. That plus making sure my 557 was being fed adequately. However in doing some research I had found that electric fuel pumps should be mounted as close to possible to the bottom of the fuel tank. In my case that means at or close to the bottom of the bilge and I was concerned about any bilge water possibly getting to the pump, or pump wiring. That, plus plumbing a return line from the elec pump, wiring, etc. I'm a believer in keeping things as simple as possible. Hence my decision to go with a reliable mechanical pump only. Which btw is rebuildable if/when necessary. That said, I do not at all think your plan/idea is real overkill, and allot of fuel systems are run with the combo. Like I said, I just decided to keep it simple.

It is an interesting question. I have a 20' Cigarette and like most of the early model Cigarette's they were equipped with backup electric fuel pumps. I have retained the setup that has a on/off switch on the panel. They were equipped with SW pumps and work great. I also use the pump to prime the fuel before starting and always run the pump when running hard. I recently re-plumbed the original fittings and hoses. Like many that have commented, i like simplicity. I added a stainless fuel log that mounts on the fuel pump that cleans up the lines. If anyone is interested I can post a photo. My feeling is, if a backup electric fuel pump gives you piece of mind and the expense and effort is not a problem, always error on he side of caution.

I'm interested in seeing how Cig incorporated the elec pump into system (i.e. where it draws from and where it discharges to, where pump mounts, etc).
I'd much rather copy a design that's known to work than try and re-invent the wheel!