2002 YZ426 Jetting???

5 replies to this topic
  • MX974

Posted February 12, 2002 - 06:28 PM


Just got a 2002 YZ426 and was curious if any of the other 2002 owners had to rejet the carb.



  • h_bomb

Posted February 12, 2002 - 06:42 PM


Not stock,with pipe yes.

  • Lackey-92

Posted February 13, 2002 - 08:57 AM


Central Texas, I have a Pro circuit Pipe and one tooth larger rear sprocket. I went through 10 plugs in 8 rides until I rejetted.

I went with a one size leaner needle (r1), with the clip in the 2nd position from the top. 168 main, 42 pilot, .3 second squirt duration and fuel mixture screw 1 3/4 turns out. The bike runs and pulls great.

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  • MX974

Posted February 13, 2002 - 09:46 AM


Thanks for the information. Mr Lackey, are you related to Brad??? Did you have plug problems after you got the pipe or before. It sounds like in stock condition it was OK. In the past I thought if you put an aftermarket pipe on, if you had to re-jet it would be richer.

I am thinking about the thunder alley pipe. Any suggestions if I do that??? H Bomb, did you have to go richer or leaner with the pipe?

Thanks, Jay

  • h_bomb

Posted February 13, 2002 - 09:52 AM


Im running a 168m and 45p no BK mod I did the BK and my bike had a little bog off idle no more it rips.

  • leatherlungs426

Posted February 15, 2002 - 12:50 PM


I am running stock jetting, exhaust but new air filter on my 2002. Lately I have been having throttle hesitation problems in the tight woods stuff.In neutral it doesnt seem to do it just when I put it in gear and only that first little bit of throttle. Its about 500 to 1000 feet and up, temp is about 40. Running regular 93 octane pump gas. Bike runs awesome everywhere else. Sometimes it will just stall after I have had to restart it for no apparent reason. Plug color is perfect. Just put 10 oz flywheel weight on it. Any advice would be appreciated.

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