RE: OS 91 FS SURPASS
Thanks Mister Biplane that worked Now to find a set of springs, Tower no longer lists engine on their parts list. Cowboy the prop is a Graupner 13.5X8 wide blade 15% nitro running at 9000 rpm. If thats too small or overrevving its time to go back to 2 strokes.
Thanks for the help guys,btw the spring was broken in three pieces. Jim