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HMMRDWN

Now I am confused.

4 posts in this topic

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.

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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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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

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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.

http://www.thumpertalk.com/forum/showthread.php?t=327405

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