Founded by Carl Marschütz on April 5th, 1886 in Neumark, Germany, Fichtel & Sachs is the world's oldest motorcycle manufacturer. Renamed Sachs Bikes, as of 2010, the German company currently produces a line of mopeds, scooters, motorised bicycles and all-terrain-vehicles. The Sachs SA-340 was a 30-horsepower two-stroke engine used in off-road vehicles during the 1960s and 1970s, including Arctic Cat's Puma snowmobile and Rokon's RT-I, RT-II and RT-III dirt bikes.
The SA-340R, a variant used by Rokon, produced 35-horsepower at 6,500rpm. With a theoretical compression ratio of 11.8-to-1, the 340R generated 28 foot-pounds of torque at 6,000rpm. A two-stroke, single-cylinder engine, the 340R yielded 6,500rpm at 83 miles per hour and gave Rokon's RT-line of dirt bikes a top speed of 90mph.
The SA-340C engine, chiefly used in Arctic Cat snowmobiles, had a split crankcase held in place by six hexagonal screws. With a three-piece crankshaft, the 340C had inseparable grooved ball bearings adjoining a Bosch magneto flywheel and separable cylindrical roller bearings on the power-take-off side of the crankcase. When needed, the 340C cylinders could be rebored twice, as opposed to three times for SA-280-series engines.
Rokon's SA-340R engines contained a 36-millimeter Mikuni carburettor. The SA-340C engine had a Tillotson diaphragm carburettor with integrated choke. Sachs recommended adjusting carburettor settings at altitudes greater than 3,280 feet. The Tillotson was the first carburettor used in Sachs engines that had adjustable jets, allowing for custom fuel-air mixtures.
Ignition and Starter
Sachs SA-340 engines had a manual Fairbanks recoil starter that supported clockwise or counterclockwise operation. All SA-340-series engines had Bosch dynamo magneto ignitions with either inertia-pinion or solenoid-controlled pinions.