Help building my first bike

Hi everyone, i'm new to the forum and this is my first post. I wish I could post on other threads before starting a new one, but I don't know much and I don't have any experience building a motorized bicycle.

I was hoping that someone could lay out and explain some of the finer details of building a motorized bike for me. I've been trying to do research and learn how to build a bike but some things are pretty confusing to me. (aka. gear ratios, gearbox reducers, etc.)

I was planning on taking an old bike and slapping an engine into the middle or behind the seat, attaching a large sprocket to the motor and running a bike chain from that sprocket to the rear wheel sprocket. (also large) The way I saw it was that more teeth gives more horsepower, but I really don't know. Can anyone clear things up for me? Thanks in advance!

Not to diminish the "do-it-yerselfers" but you might want to consider a kit for your first build - the experience is invaluable and you'll get on the road before winter hits...

mebbe, it IS Maine, winter is almost here

don't buy the kits heres a guy who built a good one
YouTube - weedwhacker, motorized bicycle
YouTube - how to build a weedeater motorized bicycle