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2005 yz450f jetting.....michigan

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Hey guys I have a 2006 yz450f with a full Fmf 4.1 exhaust , uni airfilter, and a dynojet jet kit. This is just a general question for you guys. When I crack the throttle it sometimes wants to die down. I don't remember what jets are in the kit but I put what they recommended. Any suggestions? I ride in west MI mostly on trails but I do go up to silverlake dunes a cpl times a yr.

Thanks guys

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Hi there, I'm in Northwestern PA and ride a 08 yz450f with full fmf powerbomb and 4.1 pipe. Here's what I run for jetting.

Summer Settings for 2008 YZ450F

Main jet: 175

Pilot Jet: stock

Fuel screw (turns out): 2.5

Needle model/Clip position: 4th down

Airbox lid (on or off): n/a

Pipe: FMF Powerbomb Header, FMF Ti 4.1 pipe

Altitude where I ride: 500-1000 ft

Temperature where you ride: 65-90

Now, for this time of yr, because of the cold you'll want probly a 180 main, go 2 sizes larger on the pilot and raise the clip 2 more position. Adjust the fuel screw till the bike doesn't pop. you'll have to play more with these as I haven't done any jetting for winter riding yet. With this warm winter, I've just been running the same jetting I run in the summer.

My bike starts 1st kick all year long. Pull the choke, lean the bike over to fill float bowl, 2 pumps of gas(colder weather only), and 1 good kick. It never fails. Good Luck

Edited by Yamaryder29

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