Son's 2004 WR450

3 replies to this topic

Posted April 17, 2009 - 08:35 AM


I am about to jump in and help him rejet his bike back to low altitude specs. When the bike was purchased new we put in a dynojet kit and set it to the recommended specs for the altitude ridden. The butt plug was removed and the air box drilled for more air along with an aftermarket air filter installed. A year ago a hot shot exhaust cam was installed for more top end. I would like to unlock the potential of the FCR carb. I have never really felt it was tuned properly. What are some simple fixes to help the problem ? What are more technical fixes if we get ambitious ?

  • wartsnuff

Posted April 17, 2009 - 09:40 AM


I would believe a JD jetting kit is what you are after :p

good luck
at least you have the steel frame. making jetting easy :lol:


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  • Thumper_Bloke

Posted April 17, 2009 - 01:32 PM


My bike is jetted perfectly, no need for JD. those kits are over rated.
With stock pipe, and buttplug removed, low altitiude (0ft up to 8500ft) i have:

165 Main
45 Pilot
72 Starter
40 Leak
#4 stock needle
70 Pilot air

Also, the AP spring, and AP diaphram rivot has been tweaked and timing adjusted for a fat spray when throttle is opened fast. This is crucial for the FCR.


Posted April 19, 2009 - 06:17 PM


It has always had a flat spot when rolling on the throttle before and after the DJ kit. Would one of those bolt on quick shots help the situation ?


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