Oem part number?

7 replies to this topic
  • WilfulLemar20

Posted March 23, 2015 - 03:47 PM


Okay so I need a new accelerator pump diphram and was wondering what is th difference of the 2 they both cost the same

Attached Thumbnails

  • 1427154449465.jpg

  • WilfulLemar20

Posted March 24, 2015 - 04:23 AM


Don't want to order the 2nd part and have it be to big would it be an upgrade or is it a bigger size? Any help is greatly apriciated

  • grayracer513

Posted March 24, 2015 - 06:58 AM


The difference is in the length of the button, or rivet, on the bottom of the diaphragm.  The button is what stops the pump at the end of the stroke, and longer buttons produce a shorter stroke with less output, while shorter buttons do the opposite.  The 5JG-14940-18-00 is the standard one, and you should probably stay with that.


Read these over (from Common Threads):




  • WilfulLemar20

Posted March 27, 2015 - 05:48 PM


Thanks for the advice gray hopefully it solves my problems after I moved the needle from the #6 to #4 I have had to run the bike with the choke on when I shut the choke off it will stay idling but when I try and give it gas it shuts off? With choke out it will run decent but I don't trust what the air fuel it have my screw out 21/4 turns and the header does not glow even after idling a few min thinking about getting a fuel injection kit and trying that

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • WilfulLemar20

Posted March 28, 2015 - 08:22 AM



  • grayracer513

Posted March 29, 2015 - 10:02 AM



What is the point of this post?

  • WilfulLemar20

Posted March 29, 2015 - 11:09 AM


That's the fuel injection Kit that I plan on using just not sure if it would work on my bike without a battery

  • grayracer513

Posted March 29, 2015 - 01:22 PM


But that's not the topic of this post, is it?

Related Content


100 hrs on 2014 yz450f, shim valves or replace them? by ttr230rider6

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  79 replies

Need help by Goforaride

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  68 replies

Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies

First Hare scramble tips by dhend8

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

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

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

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.