Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0

Jd jetting issue. Insight appreciated.

3 posts in this topic

Have a 99 WR400. JD jetting installed for sea level to 4,000 ft. Live in coastal California. Also installed all new jets, AP unit with longer prong...thus shorter squirt. JD call for air box cover removed, grey wire cut, aftermarket exhaust. ..all which is complete on my bike.

Stock settings: My settings:

Main jet 168 170 (per JD instructions)

Pilot jet 45 48 (JD suggests stock?)

Needle jet standard standard

Pilot screw standard external aftermarket

Starter jet 60 60

Main air jet 200 200

Pilot air jet 1 75 75

Pilot air jet 2 90 90

Needle pos. 3rd (OBDTM) 3rd/blue needle

Prior to JD installation: 4th clip and 168 mail...hesitation in 5th at WOT.

Thus, the only deviation is that I have a 48 main vs 45 suggested. Would this difference cause a "gargling" in various gears as well as deceleration popping which did NOT exist prior to JD jet installation? I checked the plug and it was not white but dark brown color, moist thin filmed and not crusty dark coated. HOT Cams exhaust cam installed for easier starting, clearances checked 3x for certainty. I will check for head pipe tightness to eliminate from popping probability.

Any insight appreciated. Joe

Share this post

Link to post
Share on other sites

Also be aware that gurgling (at least what I call gurgling) indicates too rich. Popping out the exhaust can come from either a too rich condition or a too lean condition. May want to try the red needle, or raise the clip onthe blue needle a notch...

Share this post

Link to post
Share on other sites

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
Sign in to follow this  
Followers 0