Jetting for my YZ-450F in Cal Desert???

4 replies to this topic
  • Robspring81

Posted November 16, 2008 - 10:35 AM


Got a few questions regarding jetting for my 08 YZ-450F. Just picked it up from the dealer last week and took it out this weekend. Very happy with the power and suspension. I finally made the switch to a four stroke from an 03 YZ-250 and it's definitely a different riding experience.

I typically ride in areas of the so cal desert that range from 2800-3200 Feet and the bike has stock jetting. I have looked at the jetting thread and did not really find anyone with settings set up for the so cal desert or these altitudes. The bike seems to have a little bit of a bog off the bottom and slight pop on decel. I have done some research and went ahead and ordered a fuel screw from Zip-Ty. From what I have read it seems that a little fuel screw adjustment will clean up the bottom bog...any input? Being my first 4-stroke I do not really have any prior experience to judge how cleanly my bike is jetting. If anyone has some experience at these altitudes with so cal desert weather, It would really help out.

Only engine mod so far is a PMB spark arrester insert. Ordered a Clarke 2.6 (like the 2.6 compared to the added bulk of an IMS 3.1), a GPR stab., a GYTR flywheel, GYTR skid plate, and some handguards. Should be a pretty good desert sled after that. :thumbsup:

  • Dirt Addict

Posted November 16, 2008 - 11:11 AM


i ride my 07 in the 2000' - 4000' alt. range

it was lean stock. try 165mj, 48pj, a/s opened just past popping on decel, everything else stock. should be good to go.

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  • grayracer513

Posted November 16, 2008 - 12:37 PM


Read through this:

  • Robspring81

Posted November 16, 2008 - 06:21 PM


Had already taken a look at the jetting thread, lots of good info. A good number of people fail to put the altitude for where they ride. Looking for someone in the 2000-4000 ft range with a fairly stock bike. Bueller?? Bueller anyone?? Dirt Addict, thx for the input,,,I am getting the feeling a 165 MJ and 48 PJ is prob a good starting point.

  • grayracer513

Posted November 16, 2008 - 07:02 PM


Looking for someone in the 2000-4000 ft range with a fairly stock bike.

That was the basis for my recommendation. If you spend more time at 2500-4000 than at 2000-3000, go with a 162 or try it with the 160. The needle and pilot are the secret.

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