Jetting suggestion and getting to the carb

4 replies to this topic
  • feti

Posted May 23, 2006 - 03:14 PM


Ok, I'm about 1100 feet above sea level. The bike is an '06 450F. I've tried everything with the stock pilot jet and cannot come to a compromise with it. Here's what I've done. I've turned it out to about 6 turns and the bike starts up great, sputters a bit with the throttle and deaccelleration. It won't idle. I can get it to idle when it's about 3 1/2 turns out, but it idles high. If I turn it out even another 1/4 or 1/2 it idles for about 5 seconds and shuts off.

My main problem is this: when I have it idling with 3 1/2 turns out, it has a very poor response with 1/4th throttle (didn't get above that, testing in the back yard). I can barely pull the front end up. When I have it turned out about 6 turns, even though it won't idle, the response from 1/4th thru full is perfectly how I want it.

So the question is should I go with a 45 pilot jet? Remember it's stock pilot jet, which is 42 (I believe). If I do need to rejet (I have purchased two pilots (45 and 48)), what's the easiest way to get to my carb? I took off my subframe today, because I tried the loosening of the carb clamps and turning in, so I could get to the float bowl, but it looks like what is the hot start cable is hitting the frame when I turn it. I can only turn it maybe 1/4th inch, which isn't anywhere enough to get to the carb. So, with the subframe off my intention was to get to the carb a bit easier by unattaching it and working on it while it's off the bike. Please somebody help me. Should I put the subframe back on and somehow get to the carb with it on?

  • SurvivorMan

Posted May 23, 2006 - 03:21 PM


everyone has gone to a 48 pilot and 170 main (at your altitude). to change the pilot i loosen both carb clamps, pivot carb maybe 5 degrees and remove pilot with a altered screwdriver i have made for pilot removal, takes maybe 3 minutes but you have to blindly know where the pilot is (try a dentist mirror to get an idea and then just feel for it) if you change these 2 jets your bike will feel incredible, responsive, no pop on decel, clean WOT

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  • feti

Posted May 23, 2006 - 03:41 PM


Correct me if I'm wrong, but do I not need to remove the float bowl in order to get to the jets? :ride:

  • foreverblue

Posted May 23, 2006 - 04:59 PM


I have the 06 yz450f and my elevation is approximately 1000ft. I installed a #48 pilot jet , #170 main and a tusk fuel screw out 1-3/4 turns. The bike runs perfect at the current temp 70f. When it gets warmer I plan on going to a #45 pilot and #168 main. You do not need to remove the bowl to change the jets. I purchased a tool from motion pro, and made a custom tool which allows me to change jets without rotating the carb. I live in Northeast Ohio and if you are close I can show you how to change jets.

  • feti

Posted May 23, 2006 - 05:02 PM


Yeah, I'm right outside of Warren.

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