So this is my beautiful fuel pump cousing stalling, backfire, low bike power, lean fuel and other bad things you never want to have in your lovely bike. Patient is KTM 690 SMC from 2009. I was curious why this expensive pump worked bad. All pieces together:
Inside is just an electric motor and small pumping section:
Pumping section:
All pieces:
So where was problem? My investigation results tells that is caused by that bearing:
Just see that clearance:
So... that clearance causing attrition of the pump rotor against to housing. So we can see big clearance between them where the pressure escapes.
I was very tired of looking why my bike is working very bad. I cleaned fuel injector, checked voltages on the throttle, checked with tuneecu for some errors, checked intake boot but without results. It was just broken fuel pump.
Other question is it worth over 400$ for oem part.