Need help with jetting, will not stay runing

[jt29]

Here is what I have, K&N filter, no lid on airbox, stock pipe but I cut all the guts out, and I am at about 1800ft.
I put in a #40 pilot
# 170 main
Moved the c-clip on the needle from stock
(position 3) down one (position 4).
The bike starts and will run. But it only idles for a little bit then it kinda backfires then dies. Which way do I go from here??

[stc416rider]

if it backfires it sounds 2 lean

[underpowered]

with a 170 main and the clip moved down 1, you are way too rich. try about a 155 main and put the clip back to stock.

[jt29]

I put the needle back to stock and tried a 168,165 and even put the stock 148 main back in but it still only idles for a while then dies. Could it be the #40 pilot. I will try the 155 main.

[underpowered]

does it die when you give it gas? or jsut randomly die at an idle? try cleanign the carb. mine did the same thing a few times
1. when the airboot came off whil jumping, 2. when the Main jet rattled out, and 3. when the clip came off the needle and the needle stuck. two of the three were extreme rich conditions. Are you letting it warm up before you try to rev it? mine will do the same thing if it is not warmed up.

[jt29]

No it does not die when I rev it, it just die's after it idles for a while. It is a new bike only has about 15hrs on it so the carb is clean. I think that it is two rich like you said. I am going to try a smaller main jet and maybe put the stock # 30 pilot back in.