ORIGINAL: patternflyer76

I would not worry to bad. Someone will find a way for more power, rebuilds, or something like the "animal above". Looks real interesting. You really have to know what you are doing to get a 2 stroke turning out the same power and performance as a comparable 4 stroke, say a 61 2 stroke to a 91 4 stroke. This does not just apply to the engine, but the building and setup of the airframe as well. Not everyone has the knowledge or these skills, so it is so much nicer to just be able to take an engine or ARF/Kit strait out of the box and put it together without the worries of big time modification or hours of re-engineering. A lot of SPAers love competing and are attracted to the SPA because it is affordable compared to other arenas. Also if you've been to many SPA events you would notice quickly that approx. (do not hold me to the exact number) 70 percent of the Novice/Sportsman class are flying ARF's, a (certain one) or ARC, a (certain one) aircraft. This tells the story. I don't believe I have ever seen an ARF compete in expert class, maybe an ARC, maybe. By going to nothing but 61 2 strokes with stock mufflers, there would be a lot of learning to do and the market would have to produce some new (smaller/lighter)(40-50 size) ARF's for the 61 2 strokes.

Which ever way it goes, I will still be a part of the SPA. Its great fun, and a great group of people.