Right - they made snowmobiles and 99% of the motorcycles they made were 50cc "Shriner" bikes or less. The 1976 racing bike came with number plates Magnesium wheels, the whole deal - even had ELECTRONIC IGNITION TOO, in 1976, we did not see that sort of thing on ordinary small engines, or cars for some time - presumably a factor of cost as I'd have thought its invention predates '76. But, yes it was the real deal. I've had people even try and argue the point with me that they existed - I'd bet all one would have to do is look back through the Devils Staircase hill climb to any sanction AMA type races that would have had a class for motocrosser's and would find them in there as they ate everything alive. That ignition was curious too; simple sealed up doughnut that had both the magneto coil in it as well as the triggering mechanism. Came with a factory Delorto slide carb on it and if I recall correctly it was a reed engine, not a rotary...
Yeah I once spent a day on the net looking for an example and could not walk away with anything; perhaps now something will have churned up, but there were literally only a handful made period and then even less went to the dealers that were all going belly up as it was like stock car racing; they could not enter the bikes without putting a certain number of them on dealer's floors. I only knew of where there was one - and it was in my town at the then RUPP dealer and ended up being the parts bike as literally the one I brought back to mint condition, I kid you not; these impossible to find bikes, one day the father (a man I worked with for years off and on as a welding consultant doing odd jobs and working at GM and such...) he happened upon an
IDENTICAL 1976 RUPP 125cc motorcycle laying in the ditch. Someone had rode it off into the ditch and the motor was full of water, sand, mud and such. He did not pause for a second as he was nowhere near our region and just loaded it up. I'll bet whomever was going to bring their pals back to help retrieve their bike they left behind stuck in the mud was UTTERLY pissed when they arrived and it was gone!
But anyhow, that was the one that ended up turning into the mint bike - all numbers matching, etc. All the motocross plates, fenders, OEM I think even the original tires were on it - unsure, but we surely never changed them... But yes, RUPP was noted for snowmobiles and their baby bikes. SACHS was ONLY much noted for making engines to go into snowmobiles, so the whole RUPP racing bike with a frame designed new from the ground up for one purpose win every competition possible, was certainly not their prior MO at all; yet was pretty much their last ditch effort in the motorcycle market before going under entirely with everything. Like I said, I recall hundreds of 50cc bikes in the barn, maybe some less (meaning smaller cc's) maybe some a little more (maybe) in cc's but all of them were essentially 2-cycle "kiddies" bikes or Shriner bikes - not so for this one single machine. I know this has forced everything with the triple tree way OT and I apologize for that, but it would be grand if one day someone could post a picture, or reaffirm they too had seen ridden or raced one of those rare birds as I am always told I am nuts - which given RUPP"s and SACH's product history, I suppose I can understand...
Which BTW I could be nuts, but those bikes existed...

Oh, and if this tells you anything, since I have had an eBay account - which gosh has to be 10 years or more, eBay is supposed to tell me when any 1976 RUPP motorcycles come up - or parts; anything in that displacement or for that purpose - simply racing comes online. I've never gotten a single ping relevant... I love my BMW and will love it far more for many reasons the day it is back looking like the day she was built and I may ride it again, but that old RUPP holds more memories for me than my BMW likely will be able to accumulate. I was a young man and I restored a bike to mint condition, what at like 8 or so??? Yes Duane, I'd bet there was so much stiction in the forks it was unreal, but with exception of that, something we did not know about really and there were no good sources to tell me such things, I did the best I could. So, after all these years, even though my 71 BMW-in-a-box project will be far more challenging due to its design, in many ways, it seems a larger accomplishment to restore something like that RUPP with no help, I got it running when the "older boys that knew all about that stuff" could not - and then my favorite, once it was running - the thing scared them terribly - not because it was unstable, because it was so tremendously fast. If you did not clamp onto the handlebars and grasp the tank with your knees and squeeze your ass around the seat and you just gave it hell enough that the front wheel was just ready to come off the ground - you would start coming off the back of the bike; this and its tendency to pop a wheelie in forth gear and surprise you at 50+MPH was enough for them to say, you ride that, we'll ride these little ones! lol It's 2-cycle fueled rapid acceleration could scare even a veteran rider when they initially got on it as it was nothing at all like any other 125 - likely due to the added 1/4" in diameter increase of the bore along with the decrease in the piston reciprocating weight with the Wiseco piston...