Dave:

We'll start by saying it's an OS engine, provided you haven't thrown some trash in the game. The muffler strap and the priming port give it away. Roughly 30 years old.

But the carb is not a 30 year old OS - they were all air bleed then, unless I'm mistaken. So it would seem you have indeed thrown some trash in the game. The carb really looks Magnum and not OS. See the lever? all shiny?

So, on the brand I'll go with Razor and say it is a Magnum engine, probably a 1.08.

But I'll disagree on the rpm - the throttle lever is just above idle, rpm around 2500.

Bill.

PS: What's wrong with a MAS prop? wr.