RE: ASP 108 Help
Sorry I cannot help with the needle valve but Do have an ASP 108. Have not flown it in seven or eight years now (just got bored with the airplane an eighty inch Tiger 11 on steriods) But it did reasonably well with that 13 pound airplane. At our elevation 15% fuel is norm and lesser is difficult to obtain so I found I had to run two head gaskets.
I know you are gonna ask about props but for the life of me I cannot remember (just looked at the airplane and darn there is no prop. I do beleve they were 15 inch diameter however.
The muffler is a little larger than the TT.61 Pro about 20% but you will find the outlet hole is much larger. I don,t recall the airplane being particularly noisy.
John