Chad,

Is the engine new? The new ones might do that misfire once in a while, try also with a separate battery, at least to test it, if the battery can not keep a stable voltage it will do that, I tried a TP 480mAh and it did that on the third flight.
Adjust to peak and back of 200-300RPM, that's where I set my engines all the time and works great.
Is it smoking to much on the transitions? if so you can close 1/8 (manual says 1/4) counter clockwise to lean the transition.
Also the previous advise are good to check, remember to check the valves clearance.

Regards