ZXR750 electrics.

[Tack]

I'm wondering if anyone here would be able to tell me if, when you switch on the ignition on a 1991 ZXR750, if the fuel pump starts operating straight away OR Does the fuel pump start to operate when you press the starter button and then runs normally once the engine is started.

It's just that I've noticed on the wiring diagram that there is power running into the relay from the starter button and power coming into the relay from cut out switch plus a little interesting thing........the signal wire from one of the coils is wired into the relay as well!!!

I took this to mean that the starter button is pushed...power is supplied to the relay which starts the pump then...when the bike starts....the signal from the coil activates the main power and runs the pump.


Any input would be appreciated, thanks

[SocialSecurity]

i dont know about ZXR750's specifically, but all the bikes ive had with a fuel pump (CBR250-R, 98 ZX9R) would only fire it up once the starter is engaged, and obviously stays on with the engine... engine cuts out, fuel pump stops

it would have to be a legal requirementl, incase you had a fuel leak or accident... and also carby engines with fuel pumps dont need to prime when you turn the key like EFI does

[BladeBoy]

I know, the fuel pump is powered by the relay it is powered from the ignition circuit, plus there is a connection to the tacho that increases the fuel rate as the rev's rise, this is why it has a "electronic" relay and not a simple contact type.
You are right the pump does not operate untill the engine is cranked and then starts.
Cheers,
Mark.

[Tack]

thnaks guys...much appreciated.