Got my harbor freight 26cc ryobi 4 stroker a while back, and finally had some time to begin fooling with it.

I stripped the heat shield stuff, the muffler, the flywheel and the ignition bracket and igntion save the spark plug, and got a weight of only 3lb 7oz.

This is much lighter than I would have guessed, the muffler itself being suprisingly heavy. I'm not yet sure if I want to go with a battery ignition, but it would save close to a pound of flywheel.

Performance at this point is hypothetical, but this motor is rated for 1 hp at 7k rpm, and the calc program I'm using says a 15x8 apc with 1 hp will turn 7600 rpm, so I'm going to assume a safe 7 grand rpm in real life, which should be about 7.5 lbs thrust and 54 mph pitch speed. A 16x7 should also work theoretically, making about 7200 rpm, 9.25 lbs thrust at 48 mph, but would require the motor to really make the full rated 1 hp at 7 k, not a tiny bit less.

I'm thinking the 15x8 will be enough to fly a 1/4 scale cub pretty realistically, but would appreciate anybodys thought on this.

Thanks,
Dean in Milwaukee