03 wr450 jetting question

1 reply to this topic
  • Clutchup

Posted July 13, 2015 - 06:00 PM


Hey whats up guys upgraded to a wr450 from my yz426 with wr tranny and loving the bike. Now i need some help with jetting i got the yama bog but its not bad when riding and not worried about it. My main concern is the bike had a pretty bad flat spot when wide open and would slowly pick up. So i checked the carb and found the main jet to be a 150 and pilot a 40 i changed pilot to 48 and main to a 160 and helped alot and reduced the bog now i just dont know if theres more to go i was thinking of getting a 165 and a 168 main jet and mayby richen the needle a clip. Also ive seen people install a 40 leak jet. Im located on the east coast about 1300 ft above SL

My mods are yz426 header the wr header had weird dents in it.
Snokel remived from air box
Stock Exhaust opened up
Gray wire mod and blue wire mod
Tps disconected
Stock style filter just put in a new one.

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  • Krannie McKranface

Posted July 13, 2015 - 09:29 PM


45 pilot


ncvs needle 4th clip

r&d remote fuel screw

replace the worn out slide plate seal

replace the worn out needle jet (emulsion tube)

keep the acv system

keep all the other jets stock

upgrade the apump system to modern specs




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