mtthem

I just got a new crt .5 and dropped in a .12tz(p). Over the past week ive been breaking in the engine. I havent touched the carb settings from the factory(every needle screw flush), I also left out the carb insert. The engine was a pain to start at first, i had to use 14.4v to get the engine past its pinch (which i hear is normal). Now that the engine has started i ran 1 tank at idle to get up to temp, let it cool down and ran a 2nd tank and putted around a parking lot, not going past 1/4 throttle. On the 3rd and 4th tanks i tried driving with a bit more throttle but once i get to 1/2 throttle the engine cuts out. The engine was blowin a lot of smoke so i figured it was too rich so i leaned it out (high speed needle) a 1/4 turn each time it stalled until i reached 2 full turns. fearing i was going to run too lean on a brand new engine i stopped running the engine to further investigate the situation. also, after each time the engine died a tipped the car to see if there was any oil in the pipe and there was quite a bit every time, ive never had this problem b4. has anyone else?
Is it also nessary to run the carb restrictor? ive run many engines b4 and ive never needed to use the carb restrictor.
Could the shorter pipe on the crt effect the engine?
Should I be adjusting the mixture screw? I never liked messing with the low end or mix screw.
(using a p6 plug and 30% nitro)
Any help is appreciated.