Hi Mike,
Given the loose set of rules thus far I would stick by my initial plan....get a dirt bike and rig a rudimentary set of pedals to it.....After you win the first race with this "secret" weapon, I'm sure rules would be made to outlaw this idea but at least you'd have 1 win under your belt! ;-)
I was thinking of trying to organize a motorized bike race here in Charlottesville (but haven't since I am so busy with my regular work) and thought of imposing weight restrictions of say 60 LBS or so....that would serve to eliminate ideas of taking a motorcycle and installing pedals on it (this would also effectively eliminate the Lifan idea unless an ultra light bike could be made since I believe the Lifan itself weighed something like 40 or so LBS ....I also thought of a stipulation that the same machine be human powered only for a certain distance race distance as well maybe 10 miles or so.....that would help ensure the bicycle aspect of the motorized bike remain intact (it'd be really difficult to pedal the ol YZ 250 that distance under human power....much less at fast speeds.
The other thought I had was to determine a distance to be raced and allot only a certain amount of fuel to be used.....That way if you run out (as in using a big engine) you'd have to pedal your machine....This would balance power, with economy, with making sure you can pedal your machine....
Oh well, just my random thoughts.....all kinds of rules could be made just have to agree
what rules would be good....
I believe racing would be fun and would definitely push motor biking technology ahead BUT, all in all, before we can race reasonably, I think a good set of rules and regulations would need to be made FIRST to help shape the racing machine itself...otherwise we'd be back to simply putting pedals on YZ 250's and Ninjas....
Hope this helps....if you do the YZ 250 idea we should split first prize! HA ;-)
Andrew