Wr450 Carby troubles...

[KillaWr450f]

Hey there TT,
So i recently bought a 2004 wr450. Heap of extras, it was a good buy.   
I had been riding it almost non-stop for the past week until it had started playing up.
It surges at low rpm, like in first gear. Idles rougher and more uneven than when i bought it and on occasion it backfires...no big backfires just more of a loud pop at the exhaust. There is also a more noticeable decel pop, which i wasn't worried about. Before all this it ran like it should and had none of these symptoms.

After pulling the carb off and cleaning and trying different needle clip settings i cant figure out where i went wrong. The clip was 3 from top when i got it and i ave since tried one grove either side of that, with no luck. 

The other issue i have is the fuel screw (underside of carby)....i had removed that (mistake!) and im not sure where the screw needs to be set. It is currently at 1 1/2 turns out.

If it helps, i'm in Australia and at sea level.

Thank you in advance as i've looked everywhere for answers but i cant sort this out!! 

[KillaWr450f]

Anybody? I need help 

[FORMA MOTO]

New pilot jet (don't bother cleaning the old one, the corrision will come back)

New fuel screw oring and washer

Read the 'hot to confirm your pilot setting' at the top of the forum', and start at 1 turn out with the idle as low as you can get it.

[Thommo_400f]

What Krannie said....

Pilot jet

Also check that the o-ring went back in properly with the fuel screw. 1 1/2 turns out is a good start.

[William1]

I also suggest checking the ACV diaphragm.

[KillaWr450f]

Okay, cheers. I will check that out and let you know how it goes