ORIGINAL: fiery
Found my OS 40 FSR ring. It had been laid up for many years. Spun it up on FAI (nil nitro) home brew fuel. Taipan broad blade orange composite 10x6 propeller. Idle RPM steady mid 2,000's. Top RPM 13,200. OS 8 medium reach plug first, then a long reach Firepower F6, which picked up 100 rpm's and offered lower idle. Clean pick-up even after prolonged idle. The OS 4 BK carb is superb. Exhaust note is nice and loud - no baffles in the muffler.
A nice sports .40 engine when released over 30 years ago. It still is.
That's one seriously good looking engine - I have a handful of OS 40's released before & after the FSR series, but no actual FSR's....... [
] weep, moan, weep
I do however have a Royal 45 "FSR look-a-like" engine, with a very similar looking carb & bolt on front housing. Impressive performance on the bench & now looking for a suitable pusher model to take advantage of that bolt on front housing to reverse the rotation scenario
