check out http://www.electricsupercharger.com/
i found this last night its pretty neat idea but 300 bucks for 5-15 horsepower thats a rip off!
(this is a set up for cars)

 

I think you may not be seeing the same effect as a supercharger because the fan doesn't really force the air into the carb. It just kind of blows it in there. A supercharger has a compressor to litterally stuff the air into the engine. The fan is not air-tight so it doesn't work as well. If it is strong enough you should see some power increase. I think if you make the it reliable and the power (going to the fan) consistent and get the jetting perfect, you just might have something.

 

Awesome, that's exactly what I needed to see! The web site FAQ pretty much states everything I've been thinking already.. they use a 50 amp motor on the fan, and it produces 4-6% increase in power. Not a huge difference, probly about the same difference I was experiencing in my test runs.

The site brings up a good point, why not just switch the fan on at full throttle? I thought about doing that, because you wouldn't have to mess with the jetting too much (maybe just a 155 main jet) because the thing only operates at WOT, so it wouldn't change the a/f mixture at less throttle. This simplifies the wiring a TON, all you have to do is mount a 30 amp push-button switch behind the thumb-throttle lever. This would also allow me to use a more powerful motor (like a modified type RC motor ) because the fan would only draw power for short bursts. Hmm, dangit, looks like I'll have to give this a try. I probly won't get a chance until sometime next week, since I'm going to the Oregon Coast dunes (around Flourence) this weekend, but I'll try the bigger motor and switch with some GOOD drag tests next chance I get.