2001 YZ250F quick throttle bog

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9/26/2017 4:31 PM

Ive read a million post about jetting, mods, everything... and im confident I'll find the problem soon but few questions. First, stock rebuilt 2001 yz250f, fcr carb still, but off a 2002 as mine was trashed to a seized jet. I did the mod with the wire to the accelerator pump. But its still got a dead spot when you quickly blip the throttle off idle. Timing is right on pump for the videos and articles ive read or watched. Jets are stock. But i did have to get the a/f screw out close to 3 turns to get it to idle right.

Should i go with a larger pilot first before going to a smaller leak jet? Also someone put a gutted white bros exhaust on it. Ridiculously loud and thinking thats toying with my jetting but shouldnt be effecting the normal dreaded 250f dead spot. Thanks for the help


9/27/2017 5:35 AM

The timing of the fuel shot from the fuel pump to the carb and the placement of that shot will make a huge difference.
You want the fuel shot to hit in the slide opening and not on the slide.
Back in that time period there were several videos and stories posted on Thumper Talk. You may want to check that out.

Paw Paw


9/27/2017 8:12 AM

I had good luck with a JD jet kit on my KTM. Their jetting specs are great.