08 yz450 question on JD needles?

6 replies to this topic
  • big fun

Posted December 19, 2008 - 03:05 AM


I am learning that the newer yz450f carbs have had alot of upgrades to them ex: stronger AP spring and dont need all the mods since I am not having any problems with it now. My next question is needles. My JD Jet kit came with 2 needles. When I rejet the bike for my new FMF 4.1 exhaust should I use the red or blue needle? I live in ohio where altitude is around 700 to 800 above sea level or should I stick with the stock needle when rejetting the bike? Does my carb already have abetter needle in it? Thanks for any input!!! :thumbsup:

  • grayracer513

Posted December 19, 2008 - 06:34 AM


The kit also came with instructions that will specify which needle you should use, based on altitude.

  • big fun

Posted December 19, 2008 - 10:16 AM


Is the needles that come with the kit better to use than the factory one? I read the directions and I understand using the right one for the altitude ,But are they better to use than the factory needle? Thanks for info Grayracer....

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  • grayracer513

Posted December 19, 2008 - 12:19 PM


Opinions vary. Many say they are an improvement.

  • big fun

Posted December 19, 2008 - 01:21 PM


Thanks again Grayracer!!!!! :thumbsup:

  • eddie06450

Posted December 19, 2008 - 06:31 PM


I live in Alabama at a low altitude as well and i used the blue needle and mine runs real good, dont know how it would run with new jets and stock needle did not try that. My bike is a 08 too. GOOD LUCK

  • tbrady

Posted December 21, 2008 - 11:57 AM


let's hope for next yr, Yamaha finally gives us EFI bike. I'm looking forward to doing away with jetting. I rode my first EFI bike and it was pretty sweet.

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