New 426 Jetting Help

3 replies to this topic
  • 250FRider

Posted June 08, 2001 - 02:40 PM


I just finished breaking-in my '01 426 and I have a few jetting questions. First, everytime I started the bike I had to use the hotstart. Does this mean it's running rich? Also, right off the bottom end it felt like it was missing a little bit, almost like it's getting too much fuel. From mid on up it's running awesome. Man this thing is FAST! By the way, I'm riding at about 500ft and the temp. is around 70 degrees. Thanks for the help!

'01 YZ250F
'01 YZ426F

  • James_Dean

Posted June 08, 2001 - 08:17 PM


Yes, try turning the pilot screw IN to lean the idle mixture. Check how many turns from bottomed it is also. Do not twist the throttle more than 1-2 times before or during start up.

BTW, the hot start and choke are side by side. No chance you have them confused, is there?

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  • KasperMX

Posted June 08, 2001 - 09:03 PM


I kicked my bike for 10 min. before i realized i pulled the wrong knob :)

  • 250FRider

Posted June 08, 2001 - 09:30 PM


I turned in the fuel screw from 1 1/8 to 1 turn out and it made a big difference. It starts first kick now with the choke on. The only problem is it still stumbles just a little bit right off idle. Other than that it's running much better. I haven't confused the knobs yet, but I'm sure I will my first race. :)


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