Kohler magnum 18 no gas to carb

I would install a fuse of about 5amps in the fuel pump wire.
Also keep in mind some small engine lawn tractor head lights wire at the switch is AC voltage and only works when the ign switch is in the LIGHTS POSITION and the engine has to be running. ((just throwing some general info at you to consider)

The electric fuel pump will turn itself off when it builds up a cut-off pressure so really no need for a 2nd switch.
A pulse pump is cheaper and lots of Kohler 20-25hp come out with a pulse pump.
You can find a Briggs pulse pump or a close rather than the more expensive Kohler pulse pump.
I do run a white briggs type gas filter when I use fuel pumps, red color filter for gravity fed. (the white color Briggs is a finer filter usually)


Keep in mind if the engine gets tipped or turned on it's side and the pulse line going to a pulse pump gets oil in the line the pump will not work until you clear the pulse hose of oil.

I would try to stay in the 2 psi max pressure for a fuel pump. 4-5 is pushing the upper limit of the needle seat.

I ran the positive wire into the red wire coming from lights and grounded it to the frame and it worked good. I ran a fuse holder in it. I don’t know that this pump will shut off because it was a cheapie from Amazon. Runs 2.5-4 PSI it says. No leaks or flooding and the mower runs better than ever.

Sometime you just got to try something…learn and figure it out. Sounds like you’re headed the right way.

The reason the positive shut off switch AND a shut off valve in the fuel line are used is that without those, a failure in anything like a fuel hose or carb valve can pump the gas into the engine at any time. Not a good thing and the switch and valve insure that can’t happen.