Description
- New Model Design: The O.S. Max 61FSR is introduced as a new model, distinct from the discontinued Max 60FSR. While it shares some features with its predecessor, it is not a mere modification; instead, it incorporates new elements in its development.
- Limited Common Parts: The 61FSR shares only minor parts with the 60FSR, including the piston-ring, gudgeon-pin, connecting rod, and the pressure-cast head from the later model GOFSR. The engine's piston displacement remains consistent at 9.95.3cc (0.6073 cu.in.) with a bore and stroke of 24 x 22mm.
- Inspiration from 61VF: The design of the O.S. Max 61FSR draws inspiration from the previously announced O.S. Max 61VF rear exhaust engine. It offers an alternative to the rear exhaust layout, appealing to those who prefer a side exhaust configuration.
- Front End Assembly: The 61FSR features the entire front end assembly of the 61VF, including a robust 17mm shaft with a massive valve port, supported by main and front steel-caged ball journal bearings. The front casting and 15mm intake boss are also retained.
- High-Quality Carburetor: Equipped with the O.S. Type 7D adjustable automatic mixture control carburetor, the 61FSR offers a well-designed and meticulously crafted component. The carburetor includes options for choke insert sizes, providing flexibility for different feeding methods and ensuring reliable performance.