07 WR450 jetting again

I converted my WR to a motard over the winter and just have started riding it. I had trouble with the low speed jetting , but got that pretty muched fixed with a new leak jet and the fuel screw. I also installed the JD jet kit with red needle in 4th position. I ve also searched this forum and havent found any fixes for the mid range stutter and bog problem i have. Its usually from about 1/4-3/4 throttle and happens during a steady throttle application. If i gas it hard or fast , it only stutters some. If i give apply the throttle slowly , It really stutters BAD. I ve also unplugged and plugged back in the TPS with no positive results. Anyone have any new suggestions for this problem , since it seems to be one that is common with alot of the WR's....thanks, Larry

That problem makes me wonder if your JD needle was mis-marked because what you describe sounds like a rich needle condition.......which happens frequently with the blue needle.

my bet is the pilot jet is a size too big. making the whole band just a bit fat . I have a 07 wr450 motard . And mine only stutters at about 1/4 throttle just holding it there . if I roll into the throttle or crack on it just goes no bog or shutter. I jetted my bike on a dyno with a wide band o2 sensor, and was surprised to find that the stock pj was fat and my accel pump was not working at all. so I jetted it down one size to a 42 and put on a rd powerbowl with the needle 1/2 turn out.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now