I've been running the 100 also......you shouldn't need a regulator in this configuration. I've got about 25 flights.....give or take a few and have had no problems except that I run it out of fuel because I'm, having so much fun. You say that you tached it but you also said you heard it go lean. I know no one at our field that can tune a four stroke by ear. The cahnges near peak are so minute in pitch that a tach is needed to accuratly tune it. Be sure to use a tach at all times. That would be my first recommendation and as statedin the previous post......bottom end sounds too lean.



Neo