The 309, a gasoline-based cut-off saw by Sachs Dolmar, proves somewhat difficult to handle, as it predates vibration reduction systems contained in newer models. And, like many saws released before 1990, the 309 rates as fairly fuel-intensive.
As a cut-off saw, the 309 uses a circular abrasive disc designed to cut harder materials, and contains a two-stroke, air-cooled, single-cylinder engine that displaces at 70 cubic centimetres. It has a bore/stroke ratio of 1.85 inches by 1.58 inches, and a motor fitted with a Tillotson HS diaphragm-type carburettor.
Fuel and Lubrication
The saw runs on unleaded gasoline, with a minimum Research Octane Number of 89. The fuel-to-oil ratio should be 40-to-1 with a Sachs Dolmar two-stroke oil, or 25-to-1 when using another brand of high-quality, two-stroke oil.
The maximum no-load engine speed of the Sachs Dolmar 309 hits 11,000 revolutions per minute ungoverned, and 8,100rpm governed, with a maximum blade speed of 5,100rpm.