I have a Crazy Sparrow which came with a stock 280 motor. Performance was dismal. I bought a Graupner 400 7.2v geared 2.33:1 and would appreciate any info on which prop and cell pack to use and how is that optimum setup determined. By the way, are there published specs on how many amps a certain motor will perform at its peak? Thanks.

First, I think that many would disagree with this motor choice. Way too heavy.

There are other 280-sized motors with different winds that put out much more power. I know that many who purchased the Great Planes version with the stock 280 could barely get it to fly, but had wonderful results after upgrading the motor to a more powerful version.

Hobb-Lobby.com recommends a much hotter motor combo for their version.

Shawn
eflightpower.com

With a geared 400, you can use a 9x6 prop. I'd recommend one of the plastic ones designed for e-flight.