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?