This is for grayracer513

Hello! I got a question being that everyone is asking about Jetting. I put the JD jetting in my 07 and he has me running the 48/170 combo on 93 pump gas at 1200' with temps around 75 to 80°F. After doing a lot of reading this seams a little fat at those temps? Could you give me your feedback?

I run a 45/165 in my '06 under similar conditions, and it works fine. That's the only feedback I have for you on that one.

People do tend to want to run them very rich, for some reason. Far too much is also made of a little decel backfire, as well, if you ask me. If my YZ450 never pops at all, I usually regard that as an indication that it's a bit rich on the idle circuit.

The JD kits require a larger main jet due to the fatter triple taper needle so you can't really compare to someone using anything other than a JD needle. I have 3 JD needles to try out in my YZ but on my RM125 I went from a 370 main (Mikuni) to a 430 with the JD needle. That's a huge jump so I wouldn't think a 170 is outrageous by any means.

You have a point. I had forgotten that about the JD kits. My 250F was the same way.

You have a point. I had forgotten that about the JD kits. My 250F was the same way.


And there you have it. The very first time that Gray has publically agreed with me. Ohhhh, let me roll around in it! That's the stuff. OH BABY!!!


I've agreed with you on many occasions, but I have never thought it was necessary for me to step in and affirm every accurate statement you or anyone else makes. In this case, however, you corrected my error, and rather than leave the question open for argument, I thought I'd acknowledge that.

Which is another way of saying, "When you're right, you're right" :applause:

That's awesome - both you guys are my reference point when I'm stuck or have q's - all I have to do is search the forums and there's my answer. Thanks to both of you :applause:

J/D is usually right on the money as far as what numbers to run. My 04' uses the 170 from Sea level to about 2,000 feet and it's spot on.

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