i have an os 46ax and i changed out the stock P-box muffler for one of the tower [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXJB16&P=7]tuned mufflers[/link] i started the engine and it wasnt running right even with an adjustment of the high-speed needle. will changing the muffler require a new low-speed needle setting?

thanks