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FMF Full System Jetting

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I have an 07 KX450F. The jetting is stock, per the numbers found on this site. I have an FMF full exhaust system; Power Bomb titanium header and Titanium Speed silencer. Now I've got that all out there........my problem....... When the bike sits idling, the header will glow up to the Power Bomb. As the RPMs go up the glowing usually goes away.

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what jetting are some of you using with full systems?? air screw settings?

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How long are you sitting idling? Its totally normal for the bikes to do that. Mine did it with the stock pipe. You dont notice it in the day time but its really obvious at night.

Also you shouldnt let your bike sit idling for over a minute.. with the stock cooling system and no overflow your bike needs to travel an average of 7mph to be effective at cooling with stock components.

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what jetting are some of you using with full systems?? air screw settings?

I had that same system and here is what I did... this was for 3000ft elev. to 5000ft.

Leak Jet - 55

Main - 178

pilot Jet - 48

I played with the needle position at 3 or 4.

Air Screw - Everyday was different as the Temp would change. The colder it would get the richer it wanted to be. That was where the needle change would also help...

I don't know what the elevation is where you are but these are my numbers.

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Thanks for the help thus far, i am at 0-1000ft elevation. I've read online what the leak jet does, i'm still having trouble grasping the concept of it tho. I ordered a 45 pilot jet and a 180 and 185 main for it. on the needle position are counting from the top or the bottom?? Thanks for your help.

I had that same system and here is what I did... this was for 3000ft elev. to 5000ft.

Leak Jet - 55

Main - 178

pilot Jet - 48

I played with the needle position at 3 or 4.

Air Screw - Everyday was different as the Temp would change. The colder it would get the richer it wanted to be. That was where the needle change would also help...

I don't know what the elevation is where you are but these are my numbers.

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i will let it set for about 2 minutes when i first start it, but when i come back in from riding, it will change colors almost the second i stop moving.

How long are you sitting idling? Its totally normal for the bikes to do that. Mine did it with the stock pipe. You dont notice it in the day time but its really obvious at night.

Also you shouldnt let your bike sit idling for over a minute.. with the stock cooling system and no overflow your bike needs to travel an average of 7mph to be effective at cooling with stock components.

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