r/FZ1 • u/westsideriderz15 • 2d ago

Fz1 fuel pump wiring rant

This applies mostly to the first GEN Fz1, although I’m sure it applies to other bikes.

Power leaves the battery and goes to the handlebars to the ignition. Then from the ignition it goes back under the seat to the fuse box. Then from the fuse box, it goes back to the handlebars to go through the emergency Stop switch. Then from the handlebars, it goes back under the seat to the fuel pump.

My fuel pump won’t prime at 10v. Doesn’t even try. And that’s what the voltage looks like through all of that wiring and connectors and voltage drops. Probably this week I’m going to set up a relay under the seat to provide full power to the fuel pump.

If anyone is interested in this mod, let me know and I’ll document it

2 Upvotes

75% Upvoted

5 comments sorted by

1

u/haydenkayne 2d ago

Maybe the fuel pump is trash?

2

u/westsideriderz15 1d ago

I used my power probe to inject 12v where my meter was detecting 10.5 or so and she spun right up. If anything, it’s my ignition and kill switch that have voltage drops that I should really address.

1

u/adkio 2d ago

I had a very simmilar problem with my gen1 rsv. When cranking at 10.5v the fuel injectors only got around 7-8 volts. Long story short - a complete rewire of the ecu harness and the flooding issue is never again.

1

u/westsideriderz15 1d ago

I will just throw a relay in since it’s all right near the battery. The power to the fuel pump will now become the signal to the relay and grab new power from the battery or something else.

I may also locate the fuel pump fuse up in the front fairing to reduce an entire length of front to back. In that case, it would go battery to ignition to fuse in the fairing to red switch to fuel pump.

1

u/pyro667 2d ago

Interesting, I've never had an issue, but that does seem like a hair brained way to factory wire it.