i have a question


4 replies to this topic
  • BoobZ

Posted December 18, 2007 - 07:19 PM

#1

ok here is my problem.. im in the process of adjusting my fuel mixture screw on the 426 and came across a predicament..

how do i know where to set the fuel mixture screw if i dont know where to set the idle adjustment screw?? im sure its commons sense or something but i was just wondering if it was even relavent..

like, say, if i turned the fuel screw in and made up for the idle drop by adjusting the idle screw would that work or would i solely have to base the fuel adjustment on the "crispness" and not the highest idle?

OR, would the highest idle of the fuel screw have nothing to do with the fuel screw?

how is it possible to keep the bike at 1800rpm high idle if these bikes dont come with tachs? lol

  • 642MX

Posted December 18, 2007 - 08:31 PM

#2

ok here is my problem.. im in the process of adjusting my fuel mixture screw on the 426 and came across a predicament..

how do i know where to set the fuel mixture screw if i dont know where to set the idle adjustment screw?? im sure its commons sense or something but i was just wondering if it was even relavent..

like, say, if i turned the fuel screw in and made up for the idle drop by adjusting the idle screw would that work or would i solely have to base the fuel adjustment on the "crispness" and not the highest idle?

OR, would the highest idle of the fuel screw have nothing to do with the fuel screw?

how is it possible to keep the bike at 1800rpm high idle if these bikes dont come with tachs? lol




When I adjust my fuel screw I actually turn the idle up. It makes it easier for me to hear when the mixture is right. After I'm done adjusting, I'll turn the idle back down. Don't worry about the exact RPM.

Here is the best way that I've found to adjust the screw. Start the bike and warm it up. Turn the idle up just a little. Slowly turn the fuel screw in, until the RPM's drop and the motor wants to stall. Then slowly turn the screw out until the RPM's peak. (listen closely) Once they peak, turn the screw back in 1/8th of a turn. Turn the idle back down and wack the throttle and see if its crisp.

Now if you have to turn the screw out more than 3 times to get the motor to "peak" the RPM's....then you need a larger pilot jet. If it takes less than one turn to find the "peak" then you need a smaller pilot.

Hope this helps...

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

Posted December 18, 2007 - 08:44 PM

#3

yes it deffinately did..

i just didnt know where to set the idle and all that.. after tinkering with it for a while i finally got it to peak good and get a crisp snap out of the throttle..

i used to race a fuel injected sportbike and did all the tuning through a computer so im new to the whole carb. thing.

thanks :banghead:

  • 642MX

Posted December 18, 2007 - 08:47 PM

#4

Your welcome. Nice screen name by the way.....:banghead:

  • BoobZ

Posted December 18, 2007 - 09:44 PM

#5

o ya, its the shiz right? its a life long nickname since my real name is bobby. my bro always called me boobie, then people started calling me boobz. lol.





Related Content

Forums
Photo

Is it worth it? (Cam and High compression piston) by macgi77


Dirt Bike   Make / Model Specific   Honda   CRF 150/230 F/L
  • Hot  36 replies
Forums
Photo

YZ450F 03 Sparks driving me crazy by SirAttard


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

yz250x vs 450 4t comparisons (preferably desert riding) needed by JakeNorthrupYZ450F


Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 9 replies
Forums
Photo

James Stewart back on a YZ450F by YamaLink


Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies
Forums
Photo

First Hare scramble tips by dhend8


Dirt Bike   General Dirt Bike Forums   General Dirt Bike Discussion
  • Hot  33 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.