Sup guys, I own a 2001 929 and the dyno tech had an issue while trying to dyno my bike. First off i have a pcIII, a D&D full system, flapper mod done, and the egcv wired open at the 180 degree mark. While making runs he tells me that at above 9000 rpm it starts losing fuel pressure and he can't figure out why. FPR is brand new and is functioning properly, fuel pump has been checked and is in working order, injectors have been cleaned. Brand new battery, and brand new ngk irridium spark plugs. Neither he or I can figure out what can be the cause of this. That's why I've arrived here to get info from experienced fireblade brothers. Any info?

 

what was he using to measure the fuel pressure? and what was it (fuel pressure)

 

Did he try crimping the return line to see if it still loses pressure?

If it does, you have a supply problem like a weak pump or a plugged fuel filter.
If it doesn't, then your regulator is sending the fuel back to the tank.

I think your fuel filter may be plugged up...