Yz 250 jetting (2013)

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9/25/2018 2:27 PM

I have a 2013 yz 250 that runs great. It’s port and polished, raised compression (can only run 98 and up octane), and I just rebuilt it. Has 12 hours. I am having and issue with a hesitation. You can barely tell it but when you are coasting and go to get back on the gas it wants to stutter. If I get on the gas hard it won’t. And if I am going from a dead stop it won’t. Do all 250’s do this or is it jetting? I was thinking maybe the air screw? It’s only when I like riding the gas at like 1/4 throttle. I race woods so I find myself standing up a lot and just “babying” it. It’s not a big deal but if somebody could pin point it and I could switch a jet out or something simple I figured I might as well fix it.


9/25/2018 7:52 PM

Yeah it sounds like maybe a slight rich stumble on the transition from the pilot to the needle. This is a pretty common issue with the stock slide in the YZ250. MX riders don't usually mind it but woods riders do. Lots of guys swap the slide for a #8 to lean this area out. Go in the YZ 2-stroke forum on Thumpertalk and read threads about the #8 slide. Lots of info.


Powerband in every gear !

9/26/2018 6:33 AM

Will do