cable actuation. A 5-speed manual transmission, with an optional kickstarter for the early models, and shaft drive to the rear wheel completed the drivetrain. Carburetor A constant velocity carburetor was supplied by Bing. Starting in 1980, an emissions control system was implemented in various countries, which reduced available horsepower by approximately 10%. Suspension The front forks were telescopic with a diameter of 36 mm without gaiters. 1984 and prior had a dual swing arm with two shock absorbers, model year 1986 and after used the BMW monolever, 1988 and after used the BMW paralever. Ignition Up to model year 1978, a points type high-voltage capacitor ignition was used. From 1978 onwards, an electronic ignition was fitted. Specifications Pause and Restart In the 1980s for environmental and marketing reasons, BMW initiated a move to the water-cooled K75 and K100 models to remain competitive with the technical lead of the Japanese motorcycle industry. For this purpose they wanted to give up the production of the "airhead" two-valve boxer models. This decision led to protests from customers and dealers, BMW restarted R100 production, but with modified lower output, and improved torque curve engines with 44 kW (60 hp). They later produced an 800 cc version with 37 kW (50 hp). Starting in 1985, the road versions were equipped with a single-sided swingarm (Monolever). From 1988 Paralever rear suspension was introduced, first in the GS models R80G/S (later redesignated "R80GS") and R100GS, and later in the road versions R80R, R100R and in 1994 the R100 Mystic. Sources Hans-Jürgen Schneider: BMW R 45 – R 100 RS ab Baujahr 1976: alle Modelle mit Zweizylinder-Boxermotor; Technik, Wartung, Reparatur BLV Auto- und Motorradpraxis, München Wien Zürich 1984, . Don Morley, Mick Woollett: BMW. Heel Verlag, Königswinter 1994. . Hans-Joachim Mai: 1000 Tricks für schnelle BMWs. 11. Aufl. 1988, Motorbuch-Verlag, Stuttgart. Andy Schwietzer, Werner R. Reiss: BMW Boxer alle ab /5: BMW Zweiventiler von 1969–1985. 1. Aufl. Bodensteiner-Verlag, Wallmoden 2006, . Stefan Knittel: BMW Motorräder. Gerlingen 1984, . R100RS Motorcycles powered by flat engines Shaft drive motorcycles