Checking throttle-cable play.
Checking and adjusting idle speed and throttle-valve synchronisation.
(Inspections I, II and III)
Test-drive the motorcycle until the engine is warm, or allow the engine to idle for approximately 10 minutes.
Caution! Do not allow the engine to idle for longer than 20 minutes.
Oil temperature: at least 90°C (130°F)
Push back rubber cap (arrow) on throttle and choke cables.
Use the adjusting screws to adjust play of throttle and choke cables.
Play of choke cable: approx. 1 mm (0.04 in)
Play of throttle cable: approx. 1 mm (0.04 in)
Turn the adjusting screws to adjust the play of the cables for the left and right throttle valves.
Play of throttle cable: approx. 2 mm (0.08 in)
Connect hose of BMW Synchro to vacuum adapter and connect cables to BMW MoDiTeC.
Adjust idle speed by turning the air bypass screws while checking that the carburettors are balanced.
Idle speed: 1,100±50 rpm
Note: Make sure that both throttle valves are closed.
Caution! Do not tamper with the sealed stop screws of the throttle valves, as otherwise the idle-speed volume flow will have to be reset by the manufacturer
Carefully turn the adjusting screw of the left throttle valve and reduce play until the reading of the Synchro tester changes.
Turn the adjusting screw very slightly in the opposite direction until the reading returns to its original value.
Tighten the locknut to secure.
Note: Make sure that the reading does not change when you tighten the locknut.
Adjust the right throttle valve in the same way.
Note: Zero play can cause the throttle valves to rattle.
Use the adjusting screws (arrow) to adjust play of the throttle cables.
Push the rubber cap into position over the adjusting screw.
Play of throttle cable: approx. 0.5 mm (0.02 in)
Use the adjusting screw (arrow) to adjust play of the choke cable to zero.
Push the rubber cap into position over the adjusting screw.
Move the handlebars all the way from left to right and check the settings. Make sure that engine speed does not vary when the handlebars are moved in this way.
Repeatedly open the throttle gradually and increase engine speed from idle to approximately n = 2,500 rpm to check throttle-valve synchronisation. (Readings shown by Synchro tester must increase and decrease together). If necessary, correct by turning the adjusting screws of the throttle-valve Bowden cable.
Note: Make sure that when the throttle grip is released both throttle valves return to their fully closed positions.
Tighten the locknuts and recheck carburettor balance.
Seal off the vacuum bores.