And I mean 'kid' - who's in the queue for one of these?
Not me I'm afraid. 
Don't laugh, D... if a guy can go fast on a li'l ol' 50cc, what happens when you put him on a RZ350? Those little guys blew the 750's and 1000's into the weeds all the time. I know, I had more than one 250 and 350 2-stroke F-bike rider embarrass me on my 750 superbike! Small in stature, big on skills.
I was too big to ever race the smaller displacement classes, but I always loved the little racers. Many manufactures took the tiny-cc classes pretty seriously, like Honda:
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And you can still buy one of these NSR50R's brand new, race it in the pitbike class:
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Want a 50cc street screamer for the city?:
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Some guys would take a MB5, put a full fairing on it, pipe, port & polish, and high compression piston and race it. The great thing about the smaller classes is you could enter the bigger classes and be fairly competitive, but mostly to get a lot of track time, maybe 5 or 6 sprints a day. It's really cheap racing and a lot of fun.
