Supertiger-

I balanced my Zero right where the instructions said; 107 mm from the leading edge at the center. But I did balance it without the cowl on, that may have added an ounce or so. I've only flown mine twice but it settled in beautifully - just greased in. First landing was a little hot, but the second I slowed it down more - no problem. Hoping to fly it again this weekend.

Mine has a Magnum .61 2-stroke and it goes like a bat-out-of-heck. A .91 4-stroke sounds like an awful lot of engine for this light bird. But, hey, don't want it underpowered!