2009 YZ450F with DR. D exhaust

O.K. guys this is my first post so please do not kill me. I race the vet class and the elevation that we race at is around 3000 to 4000'. I just put the Dr. D system on my bike and it seems to run pretty well. There is a substantial difference in power from the stock pipe. My question is about jetting. I did not change a thing from stock. I backfires when I let off the gas. Do any of you have this same setup and what elevation are you riding? Please advise. Should I do some jetting changes?

I read in motocross action that if you put a pipe on the 09 450 you have to go to a 165 main jet and move the needle up one notch.

O.K. guys this is my first post so please do not kill me. I race the vet class and the elevation that we race at is around 3000 to 4000'. I just put the Dr. D system on my bike and it seems to run pretty well. There is a substantial difference in power from the stock pipe. My question is about jetting. I did not change a thing from stock. I backfires when I let off the gas. Do any of you have this same setup and what elevation are you riding? Please advise. Should I do some jetting changes?

It pays to do a search before you post any questions. You will usually find your answer :worthy:

Check out this link...

http://www.thumpertalk.com/forum/showthread.php?p=3710599#post3710599

Forget the jetting, kill the NEWB!!!! just kiddin' bro, go check out the jetting database

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