Back to the ST2300 ?
I know you did not have good luck with the ignition version -but 5% nitro n alky on an ignition one sure worked for me .
The 9000 rpm on 18x8 was awful hard to ignore -
A stockengine n muffler setup we did back then (first version single outlet) was down in 7000 range but quiet and smooth and totally easy to use .
we set it up for a local friend and he still flys it .