I have head alot of confusion on whether or not the power up needle fits in the 06 150f carb, Most have said that it does not and you have to use a washer in order to raise the needle.
Since i have just attempted this on a friends 06 i can make you all aware that the power up needle does work in the 06 150f carb. We rejetted to a 115main a 42 pilot and the 150f power up needle This setup was used at sea level in low temperatures with great succes combines with air box mods and a custom exhaust.
on a stock motor i would suggest one size smaller main as your starting point.
Good luck with your jetting
cliffnotes: Confirmed that power up needle will work in an 06 crf150f carb