I need CALF. jetting for 2008 450F


6 replies to this topic
  • gtxkid

Posted October 27, 2007 - 09:28 AM

#1

I am going to go to race at Glen Hellen from Colorado next week and would like to know what to do as far as jetting.
Any suggestions for me would help.
Thanks from Greg

  • grayracer513

Posted October 27, 2007 - 12:25 PM

#2

Multiply your current jet size by 1.03. That should take you from a 160 to a 165, as an example.

  • todds924

Posted October 27, 2007 - 04:01 PM

#3

Multiply your current jet size by 1.03. That should take you from a 160 to a 165, as an example.


Gray, I have been running the stock jetting in my 08 with the fuel screw at 2 1/4, everything else stock. It seemed pretty good. When i changed to the pro circuit Ti-4, all i changed was the main jet 160-165 and it seems almost perfect. That is what i used at Glen Helen 2 weeks ago.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • mxdigger

Posted October 27, 2007 - 04:19 PM

#4

Greg,
I rode mine with stock exhaust and stock jetting, and it ran fine. Today, I rode Glen Helen with a Dr.D full pipe with a 162 main, 48 pilot, dropped the clip to 4th position, and the air screw out 1 3/4. The bike absolutely ripped. No backfiring, and great throttle response. Dr.D gave me these settings, but they said use the stock pilot. The bike was backfiring like crazy so I went up one on the pilot and it worked great. Hope this helps out!!

  • gtxkid

Posted October 28, 2007 - 09:03 AM

#5

Thankyou
This is what i needed to know.
Greg

  • grayracer513

Posted October 28, 2007 - 09:10 AM

#6

Gray, I have been running the stock jetting in my 08 with the fuel screw at 2 1/4, everything else stock. It seemed pretty good. When i changed to the pro circuit Ti-4, all i changed was the main jet 160-165 and it seems almost perfect. That is what i used at Glen Helen 2 weeks ago.

Assuming his current jetting for Colorado (assuming 5000') is right, and the temperature is the same in SBD, the 3500' drop in altitude should require about a 3% increase in jet size. Sounds like that was about right.

  • grayracer513

Posted October 28, 2007 - 09:13 AM

#7

Gray, I have been running the stock jetting in my 08 with the fuel screw at 2 1/4, everything else stock. It seemed pretty good. When i changed to the pro circuit Ti-4, all i changed was the main jet 160-165 and it seems almost perfect. That is what i used at Glen Helen 2 weeks ago.


Greg,
I rode mine with stock exhaust and stock jetting, and it ran fine. Today, I rode Glen Helen with a Dr.D full pipe with a 162 main, 48 pilot, dropped the clip to 4th position, and the air screw out 1 3/4. The bike absolutely ripped. No backfiring, and great throttle response. Dr.D gave me these settings, but they said use the stock pilot. The bike was backfiring like crazy so I went up one on the pilot and it worked great. Hope this helps out!!

You guys do everyone a favor and post your jetting in the All Jetting Specs thread. Use the template. :worthy:





Related Content

Forums
Photo

The "going back to the other darkside" adventure... by Monk


Dirt Bike   Make / Model Specific   KTM   250/350/450/505 SX-F & XC-F (4-Strokes)
  • Hot  113 replies
Forums
Photo

BIGBORE FOR YZ450F 2006? by Taattie94


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 5 replies
Reviews

Yamaha YZ450F 2017 by Chris.GVS


Yamaha YZ450F 2017
  • * * * * *
  • 1 review
  • Last review by Tommyk_55
  • On January 15, 2017
Forums
Photo

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
Wiki
WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info


Articles
  • 0 replies
 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.