TE/TC 14 TE300 made some changes to test carburation

Mine is pretty OK on power as well. I picked up a new 2015 300 xc w and I didn't care for the Keihin at all so I already yanked it and installed a Lectron carb. I'm hoping to test ride it tomorrow if the weather cooperates. It was 19f here today, not great conditions for carb dialing... Mid 40's tomorrow, hopefully.
I would recommend a G2 Ergo dirt tamer throttle tube first and always ride a gear or 2 higher and lug the bike. The G2 comes in a 200 cam and 400. The 200 is slightly softer off the bottom and the 400 is even softer. 300's like to lug. Have fun and enjoy the new bike.
http://www.g2ergo.com/store/g2-dirt-tamer/

I bought the g2 quick throttle. It helps keep my elbow up when WOT. I like it and I never have to go for a second grab during acceleration.

I just got mine Saturday. It's a Christmas present, so I won't get to try it until next weekend.