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gawarrior

Do I need to rejet my WR for a YZ Ti header and Pipe?

11 posts in this topic

I have a 02 wr426f with a yz Ti header pipe and just put on a YZ can. I have the stock jetting on the bike now. Oh, and I am in Georgia with and average elevation of about 1000 feet. Should I start tinkering with it or will it be ok with the stock settings?

thx

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If you still have the stock jetting in, you might need to re-jet since it is lean from the factory already. Indy would be the best one to answer this question though. Indy?

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If you still have the stock jetting in, you might need to re-jet since it is lean from the factory already. Indy would be the best one to answer this question though. Indy?

Thanks for the reply, I do still have the stock jetting in it. Maybe Indy will chime in :)

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I really dont have much experience with the 426 carbs and jetting. :) I am initmate with the 450's and general symptoms of poor jetting on these bikes. :p I would not rejet until I put the pipe on and evaluated the jetting at all throttle positions. I use tape and a pen to mark 0, 1/8. 1/4, 1/3, 1/2, 3.4, full throttle positions. Get the bike good and warm by riding it for at least 10 minutes. Then evaluate throttle response, pull, cutting out or popping and get back to us for jetting advice.

Pilot runs 0 to 1/4 throttle range

Needle diameter controls 1/8 range

Needle taper controls 1/4 to 3/4

Main jet controls 3/4 to full throttle.

They all overlap to some degree. We are here to help but You cant rejet until you evaluate the difference from your current set up with the stock pipe. :)

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I really dont have much experience with the 426 carbs and jetting. :) I am initmate with the 450's and general symptoms of poor jetting on these bikes. :p I would not rejet until I put the pipe on and evaluated the jetting at all throttle positions. I use tape and a pen to mark 0, 1/8. 1/4, 1/3, 1/2, 3.4, full throttle positions. Get the bike good and warm by riding it for at least 10 minutes. Then evaluate throttle response, pull, cutting out or popping and get back to us for jetting advice.

Pilot runs 0 to 1/4 throttle range

Needle diameter controls 1/8 range

Needle taper controls 1/4 to 3/4

Main jet controls 3/4 to full throttle.

They all overlap to some degree. We are here to help but You cant rejet until you evaluate the difference from your current set up with the stock pipe. :D

Thanks Indy, I am going riding tomorrow. I will see how it does and see what I need to do from there. I will report back with how it does. I hope I don't have to fool with it, but I appreciate the tips for what needles control what. :)

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I didn't have to rejet my 01 WR when I went to a YZ can...I did have to back the fuel screw out from 1 1/2 to 2 1/4 turns, but that's it. No bog, no flat spots, no popping out the exhaust on decel

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I finally checked my plug. It was lean. I changed the main jet to a 170, that is two up from stock. I think that should fix it. We will see.

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Its very hard to tell much from a 4 stroke sparkplug. They always look lean.

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From personal experience on my '04, I'd say try the 170 main & raise your needle 1 clip (move the clip down 1 notch), & go from there... asuming you've allready ridden it & found it to be lean.

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Thanks fellas. I will see how it is with the 170 main, and then I may start looking at raising the needle clip. I appreciate the help.

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