RE: S 61 parts
These parts are available:
SUPG3547 22092686 CYL & PISTON S61K ABC US$74.99
SUPG2575 22032121 CONNECTNG ROD S61-X61 US$25.99
SUPG5520 22123543 RE BEARING G61/75/90 US$17.99
SUPG4405 22121908 FRONT BEARING 61-90 US$13.99
These parts can be ordered through any hobby retailer who sells SuperTigre engines and accessories.