through an unfortunate incident, i've ended up with a pretty sweet adult trike. the kind with a big basket on the back that one would putt around on and do some shopping with. the kind i would prefer to be on as opposed to my mountain bike because i hate that thing, and have occasional vertigo related balance issues. plus i could paint it with leftover camaro paint and have it be awesome blue pearl. i do not know the specifics on how it drives the wheels yet but will be picking it up later.
i think it needs more power. electric power. the caveat is, like most of you, i'm cheap and want to do this with crap i have or can get cheap/free. it must be able to pedal as well still.
ideas? unfortunately all of the motors i have are 120V like from table saws, ceiling fans, well pumps and whatnot. i don't believe i have any DC motors. my dad might have some in his stash, he keeps every electric motor he comes across. i figured 12V for ease of car battery.
go
I've always wanted to flip one around with the two drive wheels up front and add some kind of pedal powered flywheel driving the front wheels by belt with sort of an in and out pulley clutch. Or something like that...
You could pedal up the flywheel, engage the clutch and do big smokey front drive burnouts.
For being able to continue using the pedals you will have to add some sort of over-running clutch like from a starter motor or similar. Basically spring loaded to lock in the drive direction and free to spin in the other.
Here you go: http://www.electricbicycle-outdoor-store.com/page/395652221
Google "electric bicycle motor kits" and you'll find others. I first became aware of this when I saw a 2-wheel electric bicycle @ WM. It was on sale and it was all I could do to walk away from that thing. I recall seeing a trike with a kit on it on-line but don't remember where. Google the crap out of this and see what you come up with. Share it with us if will. 
My great grandfather had one that used a small electric motor on the front fork that just had a roller spin against the tread of the tire.
A hub mounted motor in the front wheel would probably be the most practical. My BIL has been playing with these things.
However this looks interesting evelo.com
