RE: 4 stroke engine questions
I really like my RCV 58CD. Mine is in a fully cowled setup, and seems to handle it very well, plenty of power for the GP RV4. The needle isn't even really accesible with the cowling on, I've not really touched it since I setup the engine initially, save for one click leaner on the high needle last time I went to the field. Starting the engine is a nonissue, maybe 10-15 seconds of fiddle/prime/flipping time after fuel is in the tank.
I swing a 12x6 MA wide blade prop, it seems to top out around 10-11K, but after takeoff, its rare to require full throttle.
Just a nod to this engine, its by far the most friendly engine I've used ever.
eniac