Jetting 2007 yz450f stock pipe sea level california

1 reply to this topic
  • Family Man

Posted June 06, 2013 - 09:32 AM


[color=#282828][font=helvetica, arial, sans-serif][background=rgb(252, 252, 252)]My power feels a bit flat, not as crispy/snappy as I think it should. Bike starts easily when cold, usually first kick with a few whacks of the throttle. I tried to set the pilot jet with the fuel screw, cant get it to stall out, I think its telling me i may need a 42 pilot jet, does this sound right? Bike is running an oem piston and rings with SS valves, Stock exhaust. 14 hrs on piston and rings, timing chain and rebuilt head. I've tried smaller mj's and the bike doesnt seem to pull as long, like I have to short shift. [/background][/font][/color]
[color=#282828][font=helvetica, arial, sans-serif][background=rgb(252, 252, 252)]current jetting 2007 YZ450F[/background][/font][/color]

[color=#282828][font=helvetica, arial, sans-serif][background=rgb(252, 252, 252)]Main Jet: 170[/background][/font][/color]
[color=#282828][font=helvetica, arial, sans-serif][background=rgb(252, 252, 252)]Pilot Jet: 45[/background][/font][/color]
[color=#282828][font=helvetica, arial, sans-serif][background=rgb(252, 252, 252)]Starter Jet: 72[/background][/font][/color]
[color=#282828][font=helvetica, arial, sans-serif][background=rgb(252, 252, 252)]Leak Jet (if any): 55[/background][/font][/color]
[color=#282828][font=helvetica, arial, sans-serif][background=rgb(252, 252, 252)]Fuel screw/Setting: 1.25-1.75 turns out[/background][/font][/color]
[color=#282828][font=helvetica, arial, sans-serif][background=rgb(252, 252, 252)]Needle/Position: NFLR-4[/background][/font][/color]

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  • Joe_Jet

Posted June 06, 2013 - 08:09 PM


Had an 07 and it ran killer with stock jetting both with the stock pipe and FMF slip on. After the bike sat for a while it gunked up the carb. Have you rebuilt the carb or at least completely disassembled and cleaned it?

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