bypass mechanical fuel pump when installing electric pump?

[Wombat]

Should I bypass the old mechanical fuel pump when installing a new electric one, or just have both? If I bypass the old one, do I need to connect its outlet and inlet with a loop of hose?

[SCOTTRODS]

Should I bypass the old mechanical fuel pump when installing a new electric one, or just have both? If I bypass the old one, do I need to connect its outlet and inlet with a loop of hose?

Pull the stock pump. Install a cover plate with gasket. No more wondering.

[MinamiKotaro]

Just remove the stock pump completely.

[Marc]

Removing it looks more sanitary, and most blockoff plates can be drilled/tapped for a crankcase ventilation line.
I've usually left the stock pump in place (with a loop of hose connecting inlet & outlet) to provide an emergency backup. It's not a positive-displacement pump, so with no fuel demand there's very little motion of the internal parts - other than the pushrod rising/falling - so it's basically just going along for the ride.

[crvc]

Maybe it's a given but don't you need a regulator if you put in an electric fuel pump? I believe the stock carb needs 2-3psi at the float valve. Anything more overwhelms it and leads to flooding. My electric pump put out something like 20psi. I could never get the regulator low enough and gave up, going back to the stock pump.

kevin

[Max Welton]

It depends Kevin, on how much pressure the electric makes and how much the carbs need or can tolerate.

An electric pump putting out 20 psi almost sounds like an FI pump.

Max

[Jim Ed]

Should I bypass the old mechanical fuel pump when installing a new electric one, or just have both? If I bypass the old one, do I need to connect its outlet and inlet with a loop of hose?

Pull the stock pump. Install a cover plate with gasket. No more wondering.

If you want to go this route, here is a link to the block off cover:

FUEL PUMP BLOCK OFF - BUG STYLE 12-1600 ENG.-TAPPED FOR 1/4 INCH NPT (NOT DRILLED COMPLETELY THRU)

https://www2.cip1.com/ProductDetails.as ... C10%2D5625

[Wombat]

Thanks for the help guys. I'll bypass the old stock pump, and put in a loop of hose from the old pump outlet to inlet (keeping the old pump there is handy as a backup).
p.s. I deliberately choose an electric pump with low p.s.i. to suit the carb.

[Max Welton]

p.s. I deliberately choose an electric pump with low p.s.i. to suit the carb.

Be sure to measure it anyhow.

Max