99 f4 ~19,000mi.

starting out it seems fine but once it warms up it seems to like to stall at long red lights. ive messed with the idle screw to help the problem but it doesnt seem to help much. i like to put it in neutral alot at lights if that matters but the rpms will start to flutter around 1000rpms or less until it stalls. starts back up but will usually stall again unless i give it alot of throttle.

is this a result of dirty carbs? ive seen some people with similar problem and the FPR(fuel pressure regulator) might be the problem? or overheating? the fan was running when it stalled.

also if it helps ive recently replaced the fuel filter. has stock air filter. yoshi exhaust. full tank when this happened.

 

You really should never be at neutral at a red light. Stay in first incase you need to maneuver quickly...might save your life someday!

not to sure about what the problem is though, good luck, I'm sure someone on here will get you the answer soon.

 

Your fuel pump may be wanting to quit....new fuel filter so there shouldn't be a flow issue...

Especially at idle? Stalling...my guess is a weak pump....

Have you check your
Plugs too...see if it's looking ok?

 

i really dont think its the fuel pump at least im really hoping its not. it seemed to be working flawlessly when i was diagnosing the fuel filter problem just a couple months ago. others with the same symptoms as me, it seems to be the fpr or Regulator/Rectifier. this weekend ill pull the tank and check these things out but quickly going thru the manuel i couldnt find where the fpr is located. does the f4 even have one?

 

and yes its just at idle when stopped. it will idle ok for about the first 15 seconds or so then it will start losing rpms and eventually stall

 

Our bikes don't have fuel pressure regulators...

 

What idle bike set?

 

yeah thats what i was starting to think. it was set at about 1500. move it up to about 1800-2000 but it didnt really help. and yes i know its suppose to be around 1300 and thats obviously not the problem.

 

I had this problem and it was really the fuel pump. If I just could get the time back that I spent diagnosing other possible culprits...
You can try run the bike without fuel pump as it runs ok without it, that way you can diagnose if it is anything about the fuel pump, either the pump itself or the fuel relay.
Anyway, if it is the pump contacts, you can get away with a 40$ fix.

To check the regulator, measure its voltage at idle, should be 12.xx, and at a bit of throttle should be mid/high 13.xx. You can check the manual as I don't remember the exact RPM/Voltage numbers.

Do not run the idle that high, too much things can go wrong in long term with a idle that high!

Regards,

 

Forgot to post this:

https://cbrforum.com/forum/stickies-...l-pump-102151/