Fuel Screw Settings for PMB or GYT-R inserts?

As per the "woodruff key" service bulletin, my fuel mixture screw is set @ 2.5 turns out (done by the dealer). This is with no end cap (also removed by the dealer).

If you run an insert what type of adjustment should be made to the fuel mixture screw? It seems that the change in back pressure would make this necessary. I've found an extended screw replacement that will make adjustments much easier but would like to know if anyone has dialed their's in with an insert before I start tinkering with the thing.

I can see (hear) that the beast is going to need to be "muffled" a bit before riding in certain places and @ certain events. Otherwise it is going to be unplugged! Trying to get prepared for the quite events!


I would do some searches on this forum for more info on the fuel screw and how to adjust it. Uncork the bike whenever possible it runs great. Get the Gytr or Baha insert for noise restricted riding without jetting changes the stock one is to restrictive. Get the JD jetting kit from the TT store. I have rejeted this bike so often that I truely know how to set her up for hot, humid, cold, dry, low, medium and high altitudes. If you are jetted well for your conditions the insert has little effect. Stock the WR450 is way to lean on the needle. That is where the JD kit needles come in. They are flat out fantastic! I have the following needles for this bike:

STD, OBEK-P, OBEK-Q, NCYQ, NDJN, EMP, EMN, EMM. JD-RED, JD-BLUE. Save yourself a lot of frustration and possible starter gear isssues by following the simple jetting program JD has come up with for our bikes. It is truely the best set up and investment you can make. The throttle response is absolutely fantastic everywhere! Getting back to your issue with the fuel screw 2.5 turns will not cut it all year round! You will run it anywhere from 1 to 3 turns out depending on temp, humidity, altitude and your pilot jet selection. Search "fuel screw" and "pilot jet" you will see many informative posts. :)

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