05 jetting please help.

i just got a 2005 wr450 2 weeks ago. it starts in 1-2 kicks but when i took it out last weeked it was sputtering really bad at 1/2-3/4 throttle. im new to all this so i figured id ask you guys for some advice and hopefully i can get my bike to run like the beast i know it is. these are my specs


Year: 2005
Model: wr 450
Cam Timing: YZ ( if that means cut grey wire)
Main jet: 150
Pilot Jet: 48
Starter Jet: 65
Fuel screw (turns out): 1 1/2 - 2
Needle Model/Clip position: 4th
Grey Wire Mod (Y/N): yes
TPS Connected (Y/N): yes
Airbox Snorkel/Lid (on or off): off
AIS Removed (Y/N): yes
Airfilter Brand: uni
Exhaust Brand: white brothers e2
Average Altitude: 2000-3000
Average Temperature: 70-100

i just moved the clip to the 5th from the top and took it for a ride and it now it runs like it did at 1/2-3/4 no matter what. so im thinking it might need to be back at the 4th or up to the 3rd. please help me out guys!

I would change the plug, inspect the plug wire, and clean all grounds first


You jetting is pretty close.


Your description, if it is jetting, is a rich condition, so you need to DROP the needle, not raise it.


I would also recommend an R&D fuel screw, a 45 pilot, a 165 main, an NCVS needle, and replacing your needle jet (not the jet needle) as they do wear out and cause odd rich conditions.

so i changed the needle to the 3rd from the top. it feels like it has more power now. its doing 3rd gear power wheelies no prob when before it would only come up in 2nd, butit feels like it might have a little less top end pull... is that possible??? planning on changing the plug as soon as my spark plug wrench comes. its not popping so im guessing its not 2 lean. i live at 900ft and ride at 2000ft. maybe i should raise the main to a 165. i dont have one so im going to hae to go to the shop...

i did 99% of that stuff to my carb last night. im going to chang to plug tomorrow, take it for a ride and see how it looks. so do you think i should change out the main? i looked up that needle and it says its for a 2010 wr250. 

Where are you located? Or, what altitude and temperature do you see most?

A 150 main seems a bit lean (maybe)

I am at seal level to 1000 ft (new england) and I use a 170 main

(with the end cap and pipe and lid on airbox removed for better in/out breathing)

so i put in the new needle 3rd clip from the top. a 165 main and a 45 pilot. went riding yesterday and i have a slight bog on the bottom end like if i crack the throttle from idle it will bog real quick. any tips on what i should do to change it? i have bought a 160 main and i have the 48 pilot that was in it when i got it

Edited by cky450mm

Quick throttle bog is not jetting, it's the accelerator pump.


Pull the airfilter, and use a small mirror to see if the pump is squirting.


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