Needle Position AIS Kit '09 WR450

I am sure this question has been asked and answered a million times, but I could not find the answer for the same configuration for the life of me. I got my dad the GYTR AIS removal kit for his birthday and want to install it for him tomorrow before we leave for the long weekend riding trip. His bike is a 2009 WR450 100% stock. He is not interested in opening up the exhaust or intake, but has been complaining about it running lean and the stock throttle stop. I might be able to convince him to cut the grey wire if it is really necessary to make this kit jet properly. We ride mostly 1000'-6000' year-round. He will not be rejetting between seasons or elevations so if we could shoot for something that would work well right in the middle (say 2500' and 60*F) that would probably be best. I have a #50 pilot jet, a #175 main jet, a #110 main air jet and a #45 leak jet. What position should the needle clip be in for best results? Instructions say 4th from the top. Which side is the top (pointy or flat) and is this the best setting for my conditions? Do I need to cut the grey wire for these jets to work properly?

Thanks for the help guys.

For reference, I have a 2006 WR450 that I put this kit into shortly after I got it. I used the jets that came with it (don't remember what they are now) and my jetting is pretty spot on for the riding we do so I am hoping to get similar results. I am a newb to jetting as the only thing I have done jetting-wise in my 13+ years of riding was installing this kit in my WR 5 years ago.

Edited by woods-rider

Just did the kit on my 2011 and it was great with all of their parts. However, I did the peas shooter mod and removed the baffle as specified in the GYTR instructions. Only tried it at 0 to 1000 feet so far.

What position did you use on the needle clip?

For an otherwise stock bike I would start with 3rd clip, might want to go second.

Other jets are too rich from the kit.

Main go 168 or even 165

Pilot 48- 45

Thanks tribalbc, this is the info I was looking for!

For an otherwise stock bike I would start with 3rd clip, might want to go second.

Other jets are too rich from the kit.

Main go 168 or even 165

Pilot 48- 45

I believe Tribalbc is right on the money.

With all the free mods on my 07'wr450f, I was running this:

MJ 168







I never messed with my jetting throughout the year, and I was happy with the way my bike performed. I ride the NW as well, and my elevation ranged from about 0 to 4,000 feet.

When I replaced my stock exhaust for a complete YZF exhaust I moved to a:



So, I would think that if your not going to open up the exhaust or airbox a MJ165or168, AND PJ45 would get you right on the money.

You can also search the jetting database sticky to see what other guys are running with your similar setup.

as far as the grey wire...if you do a yz throttle stop...clip it...if you keep the wr throttle stop...dont clip it

Good to know

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