IL law, can I claim ignorance on a 66 cc engine?

[worthbeads]

So I have a china ~66cc (or ~80, whatever) engine I installed myself on a bike. In Illinois, you can legally drive a 49cc motorbike with just a regular old driver's license. No registration necessary. But if it is above 50 cc, I'm supposed to get a motorcycle license.

My question is, seeing as the motor has no identifying marks, can I just claim the motor is under 50cc? Can I just feign ignorance and tell authorities, "well, I think it's under 50cc"? Who has the burden of proof here? What will authorities in Illinois likely do if I am caught using a motorbike with an ambiguous cc rating?

Also note I am not in Chicago. I'm in a suburban college campus town.

 

[wheelbender6]

There are no stampings on the engine that indicate displacement. There isn't even a serial number on it.
Unless your officer has a micrometer and dial indicator, the engine is whatever size that you say it is.
If the officer catches you doing 40 mph on that thing, he will be less inclined to believe you.

 

[butterbean]

There have been a few members selling 49cc stickers, you could look around (maybe on the "other" forum, not sure). You could look into that. Or you could maybe have your own made.

 

[Sidewinder Jerry]

In most places the best way to avoid legal issues is through your riding habits. Fully obey all traffic laws at all times. Ride your bike as if you were on a motorcycle. This will keep the law off your back more than anything else will.

 

[Wolfshoes]

I am not a expert on Illinois law, but to the best of my knowledge, Illinois no longer considers engine displacement since it went to a low power vehicles listing criteria of engine/motor powered bicycles. One horsepower is 180 lbs of pulling force(horsepower definition in Wikipedia.com). A motor assisted bike rope pulled to its motor driven full speed takes about 27 lbs of pulling force. 66 cc motors are far below the 1 horsepower required of Illinois compliance. Based on a road test made locally with a rope and fish scale; bump start engines would be close to .15 of a horsepower (27lbs/180lbs).

In a 2012 Illinois Appeals Court ruling in the Decatur area; it was accepted that 20 mph added to the bump start speed was acceptable in interpreting the low power vehicle law speed limit.

I pointed out the engine was 66 cc and overrated for horsepower and the Appeals Court ruling to the local police chief. In my local town, I am good to go as a low power vehicle observing bicycle rules. This allows me to ride the main highway through town with the cars and semi trucks at my full speed except school zones. Careful what you ask for, you may get it.