RE: MVVS engines, any good??
Well I bought one specifically for this F20 about 5 years ago on the word of one guy at Morris Hobbies named "Robert. " He specifically told me that the MVVS.40 size Q500 would run equal to the YS45 with a 9/6 or 7 apc prop.
Now I won't lie here. The engine did run very well but had no more power and a common 46fx as far as I was concerned. I had countless conversations with this guy until I realized he was just "full of it." I removed the engine, sold it and bought the Jett.50