Rejetted my WR450

4 replies to this topic
  • yamaharichey

Posted January 27, 2003 - 04:24 PM


O.K. Guys, I just finished rejetting my WR450, wow what a difference! I changed the pilot jet from a 45 to a 48, changed the main jet from a 150 to a 155 (that came with the bike,)and I raised the needle one clip. I'am at 4500ft. and now it starts cold, full choke no throttle, instantly. No hesitation or backfiring and the low end power is even better. I ran it up and down the street to warm it up, then started it several times, its starts instantly with no throttle. I cruised along at a slow steady speed and it was smooth as silk. it is now the most perfect off road bike ever built!

  • utvols

Posted January 27, 2003 - 04:31 PM


Did you check your acc. pump timing when you had the carb off? Just curious how long a squirt your getting. I went to a 48 pilot and 160 main and did the grey wire mod. Bike runs much better but still a little hesitant starting without slight crack of the throttle. My acc. pump was a little less than one second and I timed it back to one second. Also were you starting bike in nuetral or in gear? I am trying to figure if it is worth doing the blue wire mod as my bike kick starts fine first kick every time.

Thanks for the info

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  • brebro

Posted January 27, 2003 - 04:48 PM


Do you recall where you have your air screw?

  • allinson

Posted January 27, 2003 - 04:49 PM


are you saying there is a gery wire modification on the wr450?

  • utvols

Posted January 27, 2003 - 04:53 PM


With stock jetting I had it all the way past 3 turns with no improvement. After jetting I set it at 1&3/4 turns out. Yes there is a grey wire and it did not effect the bike running. It will be a couple of days before I ride again to tell if it improved anything.


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