Specifications of the Stihl 031

Engine Specifications

• The Stihl 031 engine is a single cylinder, 2-stroke engine, with a displacement of 49 centimeters. The bore is 44 mm, stroke is 32 mm. The ignition is a breaker controlled magneto ignition with timing set at between 2.0 and 2.3 mm. The breaker point gap is 0.35 to 0.4 mm.

Cutting Attachment

• The Duromatic guide bars come in 16, 18 or 20 inch sizes. The Rollomatic sizes are 13, 15, 16 or 18 inches. The chain is either an oilomatic chain, sized at .325 inches or 3/8 inches, or an S-type chain. The chain sprocket is an 8-tooth for the .325 pitch or 7-tooth for the 3/8 inch pitch. It is lubricated by a fully automatic oil pump. Oil capacity is 0.6 pint.

Fuel System

• The fuel system is an all position diaphragm carburetor with an integral fuel pump. The fuel capacity is 1.14 pints and the fuel mix is regular grade gas and a 2-stroke engine oil. The mix ratio is 1:40 with Stihl oil, 1:25 with any other oil. The air filter is a flat two-piece wire mesh.

Weight & Miscellaneous

• The Stihl 031 weighs 14.6 pounds (AV model with 13-inch bar). The recommended spark plug is either a Bosch WSR6F or a Champion RCJ6Y, with an electrode gap of 0.02 inch and a thread of 0.37 inch.