The other day my '00 ZX9R began to run poorly. It was spitting and sputtering in low RPM range but not at hight RPM's. This I figured was an ignition issue or a vaccum problem. I tore everything down. I could not find the culpret for my life. I checked everything every thread on here told me to check. Then while test riding the bike it died and would not start anymore.
While the tank was off, i checked the fuel pump using all of the stock fuel lines with the springs over them. The bike started right up. I then put the tank back on and the bike would run but then die. WTF! the fuel lines were not kinked. Long story short.....the fuel line was collapsing from the fuel pump, but I could not see it with the stupid spring in the way! Easy fix!!!
I hope this helps someone in the future.
