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Jetting for FMF exhaust

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Looked all over the forum but have not seen info specific to this combo. FMF does not have suggestions for this bike. 2012 YZ125, adding a Fatty and shorty. Current jetting is the stock 430 main, 40 pilot and 2-1/4 turns out of air screw racing mx in the MD, VA, PA, WV, in the B classes. the stock jetting makes Plugs look good for our neck of the woods. Is this jetting going to be ok for the new exhaust? I have heard rumor that I need to go 1 jet leaner on the main, but nobody has said for sure.

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Looked all over the forum but have not seen info specific to this combo. FMF does not have suggestions for this bike. 2012 YZ125, adding a Fatty and shorty. Current jetting is the stock 430 main, 40 pilot and 2-1/4 turns out of air screw racing mx in the MD, VA, PA, WV, in the B classes. the stock jetting makes Plugs look good for our neck of the woods. Is this jetting going to be ok for the new exhaust? I have heard rumor that I need to go 1 jet leaner on the main, but nobody has said for sure.

That is very safe jetting for our neck of the woods, I like a 420 in the summer and if on sand in the cooler months a 430. Good gas 95+ octane is your friend.

we run a factory fatty and shorty.

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That is very safe jetting for our neck of the woods, I like a 420 in the summer and if on sand in the cooler months a 430. Good gas 95+ octane is your friend.

we run a factory fatty and shorty.

Your neck of the woods is very similar to ours, so that sounds good. I usually get input from some guy in utah or cali, which serves me no purpose whatsoever. What specific gas are you using? I don't have $$$ for race fuel, but we have always run Sunoco 93 octane pump fuel with good results.. I will probably do a plug test with the 420 before this weekend and see how it goes. What tracks you racing in NC?. Been wanting to get my son down there during the winter and it looks like this next one will be the right time.

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Your neck of the woods is very similar to ours, so that sounds good. I usually get input from some guy in utah or cali, which serves me no purpose whatsoever. What specific gas are you using? I don't have $$$ for race fuel, but we have always run Sunoco 93 octane pump fuel with good results.. I will probably do a plug test with the 420 before this weekend and see how it goes. What tracks you racing in NC?. Been wanting to get my son down there during the winter and it looks like this next one will be the right time.

NCMP, Hog Heaven, Wide Open, Windy Hill, Devils Ridge, Birch Creek are our normal tracks. I will suggest you need Race gas to ride Hog Heaven, that sand track has been the death of many

a 125, (including one of mine)

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NCMP, Hog Heaven, Wide Open, Windy Hill, Devils Ridge, Birch Creek are our normal tracks. I will suggest you need Race gas to ride Hog Heaven, that sand track has been the death of many

a 125, (including one of mine)

Thanks for the heads up with Hog Heaven. We stopped in to see it on our way to FL last winter and he said he wanted to ride it. Maybe he should dig out his yz250f for the day on that one.

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