jetting a 300ex with full cobra jet exhaust

[dwcrash]

I recently started running harescrambles and need some advice. The first one I ran my 250r but the suspension just needs so much work so I decided to run my 300ex in the last two. I've actually done better on the 300. My question is I had a cobra exhaust put on it awhile back and never checked the main jet size. Now that I've started racing it and working on it myself I noticed it still has the stock main jet (#122). Does anybody know which size is correct to run? If anybody has any good wood racing advice please let me know, I'm trying hard to make do with the 300 until Honda finally releases something new. Any help will be greatly appreciated.

[300exQuadracer]

i got a full cobra and k&n and i run a 128 main jet with the kneedle jet dropped down 1 notch and i can run it with or without the airbox lid if i want and i dont seem to have a problem,
at one local track there is a woods section and the main thing i do is scope out the track ahead of you farther than you would on the normal out in the open track watch for ruts and roots and stuff liek that and keep your finger on the clutch i like to clutch it and turn in sharp corners and just pin it in open corners,
sometimes wider axles and wide a-arms get in the way so keeping it not so wide may help with a little speed
i dont know if any of this will help you, its just what i do and i think it helps a little,