[Przemysław Dudek]

Hello everyone.
I have a 2005 CRf250R. I have a problem with getting the throttle up quickly. CRF start good. The engine runs fine at idle. When I slowly open the throttle, the engine revs well. When I open the throttle quickly (suddenly) the engine chokes and stalls or stops. The accelerator pump works, it gives fuel when I quickly raise the throttle. The fuel jet does not hit the throttle flap. What may be the problem?

Best Regards
Przemek

[Leardriver]

You have covered the bases. I would next suspect a partially plugged pilot jet, and after that plugged fuel screw passage.

Replace, don't clean, the pilot, stick something sharp up that passage, I use a dental pick, and make sure that there isn't a chunk of goo up there. There often is. Blow it out with compressed air, and reinstall the pilot and see if it is any better.

Most times, on a bike that will start and run, this fixes the problem, and everyone should do this during the spring re-commission.