I have a 2000 CBR600f4 and when idling, the bike will eventually start to die unless I jostle the throttle. I tried gravity feeding to rule out ign timing and vacuum/air issues. But as soon as I connect the fuel pump it will start to die. The relays are functioning like they should. The fuel cut off relay is receiving the ign 1 pulses to engage.

My only guess is that the fuel pump my be causing cylinder flooding. Other than float needles, what could be some other causes for this? I'd hate to order needles and be wrong. Don't really know how to check them.

Thanks.

 

Often, this is caused by either a bad pump not getting enough fuel to the carbs and in turn the bike dies down or a battery/RR issue causing the pump to stop operating at low RPM. Are you sure the cylinders are flooding and not running lean?

I had the same issue in the past where my bike would stall at low RPM (like sitting at a light) and it ended up being a bad battery not pushing enough current when the RR was not sending much current.

I have also heard of this issue when an RR is going/ has gone out. I know some people use other model CBR RR's to get the extra current (900RR i believe??)

Like I said, are you sure the cylinders are flooding?

 

The fuel pump is flooding my cylinders. Two sets of carbs and 2 pumps are doing the exact same thing. It will purr with the fuel pump disconnected. But as soon as I reconnect, it will flood and stall the motor within seconds. New float needles, clean seats. I am literally lost at this point.