Hi there, I have a 4.3 kg/9.6 lb plane that I'd like to hover. My YS91AC with 20/20 fuel and 15x8 has to little thrust. the rpm is now 9500 without exhaust (cause I lost it)

APC does not make a 16x6, would 16x4 do the trick, or will it melt the engine due to high revs in non vertical manovres?

(now, Jake, is the time to come with your expirenses )