Supercharged 4 Stroke with ROOTS Compressor OSFS120SP

This is the first run of a nearly new OS FS 120 Supercharged from OS from the 1990. I have had a NIB which I was scared to use, but now I found a FS120SP from a Vitrine, not run, but also no accessories, no box, no tools, no manual. Perfect to use.
The FS 120SP was in the 1990 for F3A flying, high torque, "low" noise.
It had a ROOTS Compressor
https://en.wikipedia.org/wiki/Roots-type_supercharger
I have no silencer, so the sound is "pure"
They came with serial No. This is 11876
Technical data:
Displacement 19,96ccm
Bore 30,4mm
Stroke 27,5mm
R.P.M 2.000-11.000
BHP 2,5 at 10.000rpm
Weight 1,03Kg

Видео Supercharged 4 Stroke with ROOTS Compressor OSFS120SP канала Motor Squirrel