[einmax]

Up to now I`m not sure how I should start my jetting.
I tried to find a good starting point in all the existing topics but I`m not sure whitch one will work best for me.
Is there a big difference from the stock twin air with removed backfire and a good seal at the intake to the high flow kit from twin air?
I have the 450 xc where whould you start with the JD jetting kit and no mods to the exhaust and air box.(everything stock)
Elevation abaut 1000 feed.
And what jetting you whould go for when i open the air box, remove the backfire screen, snorkel and with moded stock exhaust. (pull out all the "unimportant stuff")


Thanks for your help

 

[Fast64ranchero]

I'd start with a 165 main jet and a 45 pilot, do you know how to do a plug chop?

 

[einmax]

to do a plug chop is not a problem.
But I hope that I start wirth a good jetting that it`s done after the first.
Thank`s I will try it on the weekend.

 

[dan46]

I also live in michigan. For jetting I have used the stock main 170 jet, stock needle 4th clip down, 45 pilot jet and 2 turn out on fuel screw. Raced it for a year and jetting is spot on.

 

[einmax]

I also live in michigan. For jetting I have used the stock main 170 jet, stock needle 4th clip down, 45 pilot jet and 2 turn out on fuel screw. Raced it for a year and jetting is spot on.

What mods you have done to the exhaust and intake (or is this stock?)
When I use the JD needl I should use a bigger main what i now is this right?

 

[dan46]

The intake is stock with snorkel out and the pipe has the baffle out.

 

[einmax]

It was not so easy with the jetting because the weather wasnt good.
Now I ran a 185 main but its still to lean.
What main sices are you guys running during the winther we have here around 20 degr. (==> good air it seams =
I have already closed my airbox (closed the holes snorkel back in and also closd there two inlets)
but the spark plug is comlettly white after a plug chop.
So now Im wondering what sices mj I schould get.