Throttle response / power at elevation

1 reply to this topic
  • shckonase

Posted October 26, 2015 - 11:50 AM


I ride a 2008 wr450 at elevation ~ 4-8k. I rode down to 1-2k the other day and was very impressed with how much more power and throttle response I get down there. In terms of my ability to lift the front wheel, at 4-8k I can clutch up in 3rd easily but would really have to pre-load and pull hard to power up in 3rd. Down at 1-2k I can power up in 3rd no problem and clutch up in 4th easily. Is it even possible to achieve the performance I experience at lower elevations up here at 4-8k? or is the air just too thin? 


2008 wr450, AIS removed, Grey Wire disconnected, TPS disconnected, FMF Powerbomb w/ Q4 exhaust, 06 yz exhaust cam, 162 main jet, 42 or 45 pilot (can't remember), JD red needle (3rd or 4th), Air box opened up (probably more than I should have, I have to clean it often), flexjet mixture screw, boyesen quickshot 3, AP o-ring mod.

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  • Krannie McKranface

Posted October 26, 2015 - 12:04 PM


Lean out your jetting for the higher elevations]


You can use the stock 2006 YZ needle for an immediate change

The JD red needle is too rich for anything but sea level to 5 k max.

You can try the blue needle too.


If it is tough to get the fuel screw to adjust lean enough at that elevation, you can go down a size in the pilot


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