Jetting Help PLS

Dealer installed Hot Cams in my 07 WR450F did the 1/2 hour break in and valve check. Installed a pro circuit header pipe with a LEXX MXE Silencer and a JD jetting kit. Called JD jetting to help with jetting for my mods. I was told to use YZ specs for the jetting installed 170 main jet, 48 pilot jet, Blue Needle on the 3rd clip(temp is below 50), installed the large O-ring. When riding the bike under light acceleration up to about 1/4 throttle it has a sputtering type of miss. This is not present when accelerating hard. Elevation is about 500'. I'm thinking that the needle position is the problem but i am no expert.

Am i running on the lean side or the rich side or is there another problem?

I would wait for spring to fine tune your jetting. If you do it now you will be too rich come spring and warmer, fairer temps.

I just did YZ cams and a HC piston on my 07 this fall. Already had A YZ exhaust. Didn't seem to make a huge difference to my previous jetting but I'm waiting for spring to fine tune.

i had the same issue with my '04 i used a jd jetting kit and e-mailed jd before i installed it he gave me a different spec than what is listed in instructions if i remember it was 170 main red needle on 5th clip counting from the top stock pilot and fuel screw

1 3/4 turns out what i had was an excessive stutter 1/4 to half throttle it is about 95% gone i can live with it ,i was loosing my mind with the stutter,try e-mailing james at he is very helpful good luck

Edited by yams

Toke out the JD Blue needle on the 3rd clip and replaced it with the JD Red on the 5th clip removed most of the sputter/miss what is left i think is normal. Bike pulls hard all the way through the power curve. Temp is about 55 today and the red needle on the 5th clip seemed good so i may need to go to the red needle on the 4th clip when the temps warm up?

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