Anyone have any history with going from the mechanical fuel pump to electrics on 500 EFI's , or any Merc Racing EFI's?

Was looking at the Holley Red Pumps that are set at 7PSI to feed the stock electric pumps. Not sure if 7 PSI is enough (though flow should be there) or the best way/location to mount the pump.

I know electric to replace mechanical may have drawbacks. But water pump failures due are more common due to the lube problems in those applications.

Weldon 1100A pump will do you. Plus its the only pump that is designed to draw fuel and not gravity fed. I have them on 3 boats and super quiet. You could use this as a stand alone pump with regulator. I'd run an Aeromotive regulator.

Alot comes with switching up fuel pumps. I used a weldon but had to install a new switch that can accommodate return style system, along with a regulator and return lines to both tanks

Not really a drop in solution

Isn’t the 1100A an Aeromotive? I looked at that as well, its the setup recommended by Whipple.

The Holley setup seems simpler as it still uses the cool fuel. The Aeromotive needed a small cooler /rrturn which I don’t understand how to setup.

Thanks for clarifying, confused with the A1000 Aeromotive

Thats the one.

Didn't realize Merc had a 'fix' for the vapor lock situation( Kit 862264A2 ) any one have luck with that? Nice simple package from what I can see (all the viring and plumbing is included - with instructions for people like me with little real understing of the fueling side), curious if it works well for stock Mec applications?

I installed it on an old 27 Fountain I had with 502. That thing wouldn't start for $hit after being rafted up for a while, was towed in so many times - wife was always scared to shut off the boat. I tried everything until I discovered that pump kit that Mercury has. It ABSOLUTELY cured the issue on that boat. Very easy and quick to install. I did not install the backflow valve that they also prescribe may fix the problem. There is a service bulletin that shows the pump kit.

Terry

I'm ready to jump on that kit now, still no regrets of buying it ?