On my first Wonder I had a Norvel,way to tempermental,might start, might not,my third and last Norvel, went to a .20 flew nice but couldn't move fast enough for our club combat,went to OSFX.25 and can catch them all! Plane was a blast,full speed made a 180 and the wing went tumbling through the air and the fuse became a yard dart .The plane flies great with the FX.25 but the wing hold down area needs to be beefed up or the wing will rip out on high G turns Also found out the Wonder isn't much on combat,first mid air and instant sawdust.[]