yz450f bogging with jd kit

6 replies to this topic
  • x2stroker

Posted December 27, 2004 - 08:20 AM


yz450f bogging with jd kit

Guys - I'm having some jetting problems. I cleaned my carb this weekend and installed the jd jet kit on my 03 yz450. I followed the directions and installed the 170 main and the blue needle with the clip in the 4th position. It started ok, but bogged horribly anywhere past 1/4 throttle. In fact, the antifreeze was bouling out of the overflow. So, I took the 170 out to reinstall a 165. In doing so, I realized that the 170 had broken off at the threads.... I reinstalled the 165 and put the clip (on the blue needle) to the 3rd clip position. It's still bogging like crazy. I live at sea level and the temp is in the 30's. My bike did not bog at all before, it was running fine... I was just looking for a crisp response.

Also, I installed the zip ty fuel screw as well. Could that be contributing to the problem?

Please Help!

  • yz400fl1

Posted December 27, 2004 - 08:25 AM


You could put a big fan in front of the bike to keep air moving through the radiators. That is what I did yesterday when I was tinkering with mine. But I have a 400 so sorry I can't help you with the jetting. I'm sure someone knows.

  • x2stroker

Posted December 27, 2004 - 08:34 AM


Thanks for the advice.

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Posted December 27, 2004 - 08:46 AM


Leave the stock jetting in the bike. They run fine with it. More than you could ever use.


Posted December 27, 2004 - 09:30 AM


Cleaned the carb hhmmm let me see. Check and make sure that nothing happened to accelerator pump and its mechanism ( timing screw and duration screw). Check the pump diaphragm, o-ring and spring.

  • BC3

Posted December 27, 2004 - 10:39 AM


make sure all the parts are in place that belong to the FUEL SCREW

spring, washer, O-ring in that order.....2----2 1/2 turns out at first....
the coolant boiling out kinda worries me :cry: How long did you run the
engine with it just sitting there?
If the main jet was broken off at the threads that would put the fuel level
that much lower than where it should be........I would just put everything back to stock and while you have the carb off work the slide linkage and
make sure the pump is squirting fuel.......


  • x2stroker

Posted December 27, 2004 - 10:43 AM


Can the fuel screw cause mid range bogging :cry: ? I did not see the o ring when i added the zip ty... :cry:

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