checkmate91

I've just fired up an ST S90, a 2-part crankcase model from the 1980's and would welcome any thoughts, advice and experiences that you may have gained from operating this engine in the past.

I got the engine from a work colleague who retired from model flying in the late 1980s and he gave it to me, attached to a 1/4 scale Precedent Aeronca Champ, when he found out that I flew R/C.

I'm keen to find out how it flew back in the day and what you suggest using it for now. Compared to my current OS91FX it seems a more revvy and "snorty" engine and not at all suited to the Champ. I bought a modern quiet silencer for the ST90 as the original was little more than a cigar tube, no baffle and quite small in volume.

I'd be very interested to know what prop was recommended for this engine originally. My example came with a MAS 13 x6 which in my experience is too small. I have an APC 13 x6 on my OS55 AX and my OS91FX is perfectly happy on an APC 15x6. So is it a revver or plodder? Thanks in advance...

Regards,
Andy

checkmate91

Er, just read the recent post about a similar engine. If the decades don't have any influence, please ignore my post. If, on the other hand, there were differences, please elaborate...

Thanks,
Andy