Don't use it
First of all you have to be able to use the bike as if it did not have a motor. Back when I sold bikes I had people stand over the bike and if it was a road bike you should be able to pull up a good inch and a half. For a mountain bike it was a good three inches stand over hight. Before anything else that was the starting place. Today many bikes have a upwardly sloping top tube so you need more stand over room than you did ten years ago. I personally don't like this design because its not as efficient(to me it looks dorky too). The more upright your upper body is the more air resistance you create. Be that as it may, I highly recommend you get another frame, something that you feel comfortable riding without a motor before you power it.
What I did was I went to the local used bike shop (city bikes) and picked up an old Giant mountain bike and converted it over to my needs. I shelled out about thirty-five dollars for it and its still working today.
When my current motorbicycle engine blew up I se it up as a "get around" bike I installed a front derailleur and a small front chainring and road it till I got my new set up going.