Francis,

Congratulations on your new engine, what a great present.
I used to run an identical engine for many years in a Keil Kraft Mini-Super with 3-channel R/C - my first multi-channel ship, in the mid-70`s
That plane had a span of 48" IRCC (plans are available from Ben Buckle in England)
I used mild standard fuel & 9/6 - 10/4 props. It throttled great and had a wonderful muted rumbling sound with the twin silencercs, but wasn´t very powerful by today´s standard.
Easy starting, very pleaseant engine - I loved it.

Finally wore it out and couldn´t get spares so I switched to a PAW 19. The plane was so oil-soaked & heavy, it needed a power boost anyway!

Run it & fly it, I think you´ll love it too!

Tomas H.