personally, I had 2 dead sticks on my MVVS 35 and I believe it was do to too lean on the low-end, so richen up your low-end needle and fly again, but keep flying around the landing strip LOL

I will comment on props,, my PA (ARF 80 inch span) Gee Bee Y is rather fast at full throttle, and this plane sure is not as fast as your Sundowner,, I use a 3W 20x8 and I can get 7100,7200 tuned for flight, peak RPM is 7370..