Don't hate me, 2000 yz 426 throttle issues

[daraj315]

So I recently purchased a 2000 yz 426. The guy claimed it has abig bore kit on it, but that was all he said. Now when I went to moon rocks it was great! But every time I Crack open the throttle it dies. If I roll it on it reacts just fine though. So I did what any other self respecting guy would do and searched the internet for mods to cure this problem. I did the BK mod and it did absolutely nothing at first. I got the timing to just miss the slide and the duration to .5 seconds. So I assumed it might be my air/fuel screw. I took it two turns out and it messed everything up! It had no reaction to throttle till it was about a quarter open. It barely ran. So now the fuel screw is out about 3 1/2 turns. It's still doing the same thing, but only when I'm riding it. I can't even roll the throttle on anymore. I'm so confused!! Also I put my needle at three notches from the top, it was at 5. Elevation 5000ft. Temp 70°. Please excuse my stupidity. Help me....

[Thommo_400f]

It's all in the jetting...

Patience and methodical tests is the way to go.

Get a new pilot jet.

Check the o-ring on fuels screw as they perish or can be split or missing.

Set everything to stock and test from there. Set the fuel screw by the stickies from William.