Dave, I have an ASP .75 stroke, which is identical to the Magnum engines and it runs very good. Lighter than my ST G75 and put it to shame in terms of power output.

The Magnum/ASP are obviously not OS-class engines, but if budget is one major consideration, they are a good choice. Just Engines has the ASP 1.08 on sale right now. It weights exactly the same as the .91 and you can buy a BCM Pitts mufler for some US$30 more, together costing no more than what you'd pay for the nearly identical Magnum XLS91A. Not a bad deal for bang for the buck.

Irvines are very nice. The Jetstream carbs are superb. I would buy one if I don't already have 2 .75s. Too bad they don't make a .91 class engine.

Enyas are great engines that are comparable to OS quality, with prices to match.

The GMS 76 is another good budget choice. AFAIK, it is the only ringed available .75-class 2stroke since the new ST G75 is not available yet.