As my title says I am new to this and it is an idea I have been kicking around for some time now. I will cut to the chase if I wanted to take a small engine from some thing what would the minimum size need to be or what would a good engine to look for be? Additionally it doesn't seem like any one uses the bikes original sprockets and chain is that just a misunderstanding on my part or is there a reason for this? and finally what kind of budget is typical and how long do most of these projects take? sorry for all the questions but my interest is peeked thanks in advance for your time and responses.