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WR250 starting problem after mods

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This what I've had for the last year, and had no problems other than running a little rich:

Model (YZ or WR 250F):2006 WR

Timing (WR-YZ):WR

Main jet:180

Pilot Jet:Stock

Fuel screw (turns out):3/4

Needle model/Clip position:JD blue, 4th

Airbox lid (on or off):Snorkel off, holes cut

Pipe:Stock, GTYR insert

Altitude where you ride:0-1500 ft.

Temperature where you ride: 60-95

Other mods:AIS removal, gray wire, ZipTy fuel screw,YZ throttle stop, ACV diabled

This weekend I removed the rear baffle on the stock pipe, and set the cam timing to the YZ setting. Before I would twist the throttle one time and hit the button and she'd fire right up, now the bike won't start unless you hold the throttle open 1/4 of the way, idles funky and has a little bit of a bog again, although on test rides definitely has more power. I tried adjusting the mixture screw and switching around jets, and it seems like it's still running rich because going down to a 175 main seemed to make it better. Any ideas?

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Well, I figured out on my own you can't just switch the YZ timing. Going back out to the garage to put it back. Son of a bitch.:thumbsup:

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Yeah, the late model WR's it is not a simple 'move a tooth', you need to use an actual YZ cam.

Yes, your jetting is rich. Put in the 175 main, move the clip to the third position from the top/flat.

What size leak jet? Typically, these bikes like a #40 or #45

Finally, try setting the fuel screw at 2 turns out. Even though it probably runs pretty good at 3/4, opening it more will reduce/eliminate any 'hanging idle' and minimize popping and backfires.

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