A little back story, about a year ago my 99 CBR F4 (track bike) stopped running. It turned out that is was a bad battery, but while it wasn't running I pulled off the carbs and put a jet kit in it and found a short in the subharness for the coils. Replaced all of that and now when I have the enrichment circuit (choke) on it will idle at around 1400 (has a new programmable ecu that i can see everything). If I close the enrichment circuit it dies. If I have it running (choke on) and try to open the throttle it dies. If I play with the throttle a bit and get it above about 2k rpm I can keep it alive. If I jump the fuel pump relay it seems to do alot better, so I'm thinking it might be the fuel pump relay, but am not sold as to that is what it is. Any suggestions would be much appreciated.

 

Anyone?

 

What is your idle set to without the choke on? With my bike if I have the choke on it idles at 2500 rpm so 1400 sounds low. Also what octane fuel do you have in there? My bike runs like sh*t with 91 but when I give it 87 its fast and stable.

 

87??? What the? is that stanard in the states? I'm running Optimax here which is 98...

 

yep 87. I know there are different ways to calculate octane, but I'm not sure there is that big of a difference. I had my bike tuned for 87 though so when I put higher octane stuff in I have poor performance, don't really know why but hey its cheaper and as long as I buy quality gas things will stay clean.

 

If I up the idle too much it does the same thing, in essence is it just opening the throttle right? Also I'm using 89, however the gas is a bit old so I'm going to dump it and try some fresh, also I pulled the carbs and ran some cleaner through them again. My setup is a BMC race filter, Moriwaki full exhaust, and a Factory Pro Jet Kit. I'm curious if for some reason my pilot screw settings are off. Anyone with a similar setup that might have the turn out for the pilot screws?