Can anyone tell me what kind of motor/bike this is?

http://www.pinrepair.com/minibikes/speedwayinfo.htm

Looks like a Suzuki motor 

Yes- as ohiomotoxer correctly writes, a Speedway.... If you close up on the seat can see the name.

At first I incorrectly thought it was the Sachs 80cc engine but that has the Fuji 100cc engine (Japanese-model F500k, 5speed 10hp). Seems this engine was also used in some Indian and Hodaka models of a similar time.  The model you have there is the 1973 Enduro, as the cool link ohiomotoxer shows if you delve into it.

Cool little bike really in my opinion, little bit of history. I love the 70's minibikes in all their quirkiness, especially the faster and stranger ones! I bet some 60 year old kid would love to have one of those again and re-live his super childhood times!

Speedway?  Interesting....

In my neighborhood we had Steen's, Chaparral's and Rupp's with the same 80 or 100cc Fuji/Hodaka powerplant.

Don't remember Speedway's though.

Yes, that link/article on Speedway that ohiomotoxer posted made a great read and was very informative. Maybe he has more info and stories?
I had heard of Rupp before (distantly) but did not know of Speedway and the fact that they were both from Mansfield as well as a former Rupp employee forming Speedway, as the article stated. So they have tons in common it seems.
Also it seems big similarities between the two marques, as well as them both using the Sachs, Fuji and Tecumseh engines. It appears the Sachs engined 125 was maybe the one to have but the Fuji 100cc and Sachs 80cc seemed fairly well regarded also.

Another interesting thing is that in 1973, it seems both companies went head to head with 125cc Sachs engined Motocross bikes. The Rupp had an upward swept pipe on their version (RMX125), where as the Speedway used a low pipe on their bike (Super Spyder). Also the Speedway promo catalogue of 1973 mentions that their version won the Winter nationals. Comparing the two bikes though, the Rupp RMX125 looks much better made to me, of a very high build finish and more like a proper Mx racer. Had some nice parts on it also, girling shocks, akront rims, showa forks and ally hubs amongst other nice parts. The Speedway Super Spyder looks much cheaper made and reminds me abit of some of the early Italjets and Aspes of a similar time.

Seems that Rupp only used the Sachs engines in their MX bikes, where as Speedway also used it in their road going trial models and what seems to be the most collectable and rarest bike they made, the road going 'Super Shadow', only a few were made and are now very collectable it seems, often commanding high prices. Also seems both companies also used same kind of quirky and similar names even, for example the Rupp made the famously named 'Widow Maker', where as Speedway offered the 'Black Widow'. Best name for me though has to be the Speedway 'Super Bitch'... !! Just how cool a 1970's name for a bike is that! Turns out though this was not a true Speedway but a one off that someone made out of a Super Shadow and re-named it a 'Super Bitch'. Very cool idea, fitting and unsurpassed!

I wonder if there was animosity between the two companies? Or if they got on and even shared ideas?
I would think more likely the former, given that they must have competed with each other, sales wise and the Speedway founder being a former employee of Rupps.

What a cool era and bikes, things seemed alot of fun back then, life was good!

Moto Minarelli engine?