Now I am confused.


3 replies to this topic
  • HMMRDWN

Posted May 31, 2008 - 02:22 AM

#1

I put a 48 pilot in my 08 YZ450F. When it was colder out with a 45 in it I had to run the fuel screw at 2 1/2 turns out.

Now that I have the 48 in it I tested it on a little bit warmer day and it ran the best at 1/2 turn out.

My question is: As it gets warmer am I suppose to be leaning it out? Meaning turning the fuel screw in? If so then I need to go back to the 45 because I have no where to adjust to.


Everything is stock except for merge AP spring and full FMF 4.1 exhaust.

  • mxracer206

Posted May 31, 2008 - 02:53 AM

#2

You are correct, when the temp is colder you need more fuel, the same reason you have to use the choke on a cold motor so to speak. I would put the 45 back in for warm weather if the fuel screw is in that far.

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  • Ga426owner

Posted May 31, 2008 - 05:59 AM

#3

Yep cooler winter = richer
warmer summer = leaner
I usually change mainjets, and fine tune with pj's
1/2 turn on fuel screw is not enough - over 3turns is too much
range for me is 1.5 - 2.5 turns out

  • grayracer513

Posted May 31, 2008 - 06:53 AM

#4

I put a 48 pilot in my 08 YZ450F. When it was colder out with a 45 in it I had to run the fuel screw at 2 1/2 turns out.

Now that I have the 48 in it I tested it on a little bit warmer day and it ran the best at 1/2 turn out.

If you are running at 1/2 turn out, your pilot jet is too large.

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