[isacguy]

I have read on several posts about the F3 fuel pump and trying diagnose it. Is it supposed to engage as soon as the key is turned on? Or while it is cranking? Is it supposed to run constantly while the bike is running, or pulsate? If you do a flow rate check (let it pump into a bottle) what can you expect? I know what it should be for a car, but I am new to bikes, so I don't know much except what I have learned from cars. My bike had sit for a year (previous owner), and started without much trouble, ran good for a few minutes, then got kinda groggy, so I pulled the plugs and replaced them, and a new fuel filter, also got some seafoam. Last night I cranked on it for 5 min, and it wouldn't start. I am afraid that some residual crap in the bowls must have clogged a jet, but if my pump isn't working right, then how will I ever diagnose anything?

[Jetpilot07]

if the pump isn't running, disconnect the cables from it and wire them dirrectly to a 12 volt source to ensure it even works, if it does, good, that may indicate a bad relay...

[isacguy]

Thanks, i'll give that a try tonight when I get off work, Good luck overseas, we appreciate all you do.

[PEM-954]

On carb models it only runs when the engine is cranking - roughly about 1 pulse every 3 seconds at 3000rpm. The fuel pump is probably a mitsubishi unit that is also used on other Hondas & Jap bikes ie Kawasaki. They can fail or work intermittently due to the electro mechanical contact pads in the back-end under the black cap.

[Walshman]

Originally Posted by PEM-954

On carb models it only runs when the engine is cranking - roughly about 1 pulse every 3 seconds at 3000rpm. The fuel pump is probably a mitsubishi unit that is also used on other Hondas & Jap bikes ie Kawasaki. They can fail or work intermittently due to the electro mechanical contact pads in the back-end under the black cap.

Very helpful... Thank you.