Bob,

I like where you're going with the ST 2300 idea; using the standard muffler, it would swing an 18x8 or 17x10 @ 8,000 rpm on straight FAI fuel. The 18x8 would provide you with 8% more speed and double the thrust of your current 90 two-stroke setup for a 10oz (283.5g) weight penlty. If wing loading presented an issue, you could save 10oz of weight over the standard build using carbon fiber parts.

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Schpankme