2002 wr426f question


8 replies to this topic
  • regulate12345

Posted May 10, 2009 - 10:53 AM

#1

This question has probably been asked thousands of times, but i keep getting many different answers. The bike is completely stock with these free mods. Cut Grey wire, set throttle stop to allow for full throttle, removed baffle, and removed air box lid to allow more air. The bike runs good but sometimes when i hit the throttle it bogs down bad. I was just wondering what the best jet set up would be, thanks alot!

  • pablo83

Posted May 10, 2009 - 11:12 AM

#2

what's your elevation?

  • regulate12345

Posted May 10, 2009 - 12:54 PM

#3

i believe around about 300' above sea level, thanks for the help

  • pablo83

Posted May 10, 2009 - 09:23 PM

#4

start with a #50 idle jet. Make sure your mixture screw is set right. And for more advanced info on the accelerator pump, refer here.

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  • Pooley

Posted May 11, 2009 - 02:39 PM

#5

This is my bike, it is an 01, but is identical to the 02:
Year: 2001
Model (400 - 426 - 450): Yamaha WR 426
Cam Timing (WR/YZ): WR timed
Main jet: 168
Pilot Jet: 45 (or 48, I don't actually remember)
PAJ: 100
Leak Jet: NA
Starter Jet: 65
Fuel screw (turns out): 2 turns out
Needle Model/Clip position: JD Red #4
Grey Wire Mod (Y/N): Yes
TPS Connected (Y/N): Yes (not re-adjusted from factory)
Airbox Snorkel/Lid (on or off): Airbox lid off
AIS Removed (Y/N): NA
Airfilter Brand: Twin Air w/ No-Toil Oil
Exhaust Brand: FMF Q
Average Altitude: 700ft (Michigan)
Average Temperature: 70-90 F
Average Humidity: 70-90%
Degree of Satisfaction (0-10): 9 (we can always want more can't we?)
Additional Mods/Comments: Additional mods:
Light Blue Wire
O-Ring Mod
ACV disabled (which is why I have a 100 PAJ rather than a 75 stock)
YZ throttle stop

This is the list of my bike settings/mods. I had the same settings using the stock exhaust can with they GYT-R tip. The combination of a new exhaust and O-ring mod were the 2 most dramatic thing done. It cleaned up the low end bog, and unleashed a lot of extra power, especially down low. I did the BK mod to the carb and personally found that the O-ring mod was far superior, so I no longer have the BK. The carb should still be tuned such that the spray of gas just misses the slide. I MAY have gone from a 45 to a 48 pilot when I went from the GYT-R tip to the FMF Q pipe.

I used to have the dreaded bog down low, but properly jetted you can basically tune it away.

  • pablo83

Posted May 12, 2009 - 06:18 PM

#6

what's the O-ring mod?

  • Pooley

Posted May 15, 2009 - 12:10 PM

#7

Check this thread for more info.

http://www.thumperta...ad.php?t=521725

  • pablo83

Posted May 19, 2009 - 06:33 PM

#8

Check this thread for more info.

http://www.thumperta...ad.php?t=521725


The O-ring mod rocks. I had noticed my AP was working poorly and was wondering how to fix it. This mod is exactly what I needed. Bog is now gone. I owe you a beer.

  • Pooley

Posted May 20, 2009 - 09:07 AM

#9

The O-ring mod rocks. I had noticed my AP was working poorly and was wondering how to fix it. This mod is exactly what I needed. Bog is now gone. I owe you a beer.


Good to hear:thumbsup: That mod was far and away the best I had ever done for performance.




 
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