Accelerator Pump Screw


2 replies to this topic
  • Unibomber

Posted April 03, 2004 - 03:45 PM

#1

What does it do.
I think this is just on 03/04s The manual calls it the accelerator pump adjusting screw.

What does it do, what would adjusting it do. :)

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

Posted April 03, 2004 - 10:00 PM

#2

It adjusts the squirt of fuel when you first turn the throttle. If you are bogging from idle, this is what you adjust to get rid of it (and maybe a #40 leak jet).

Jerry

  • skthom2320

Posted April 04, 2004 - 02:56 PM

#3

There are two things to consider about the squirt from the AP (1) the timing and (2) the length.

The AP screw controls the timing of when the squirt starts.

The leak jet referred to in the previous post would adjust the length of the squirt.

The timing of the squirt is very critical to having a snappy off-idle response. You can adjust it 1/4 turn at a time and use the seat of the pants method to find the best position. When it is not adjusted properly you will have a terrible bog.





Related Content

Forums
Photo

Megabomb Fitment by 288yz450


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply
Forums
Photo

BIGBORE FOR YZ450F 2006? by Taattie94


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

YZ450FX OR YZ450F by MESSMAKER


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  30 replies
Forums
Photo

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
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
 
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.