Maintenance - Minor Service

4. Lubricate the controls and stand pivots

The front brake lever can be removed by unscrewing the locknut and unscrewing or tapping out (as applicable) the pivot pin or screw; withdraw the lever, noting the presence of any shims that may be fitted. The clutch lever can be withdrawn similarly, after the cable adjusters have been slackened and the cable end nipples have been withdrawn from their respective levers. Note that a slotted nipple retainer is fitted at the handlebar lever (also at the gearbox end on some models); this must not be allowed to drop clear and be lost.

To release the throttle cable, first remove the injector cover (where fitted), then rotate the cable pulley inwards and carefully disengage the cable end nipple from the pulley. Withdraw the cable from its stop on the throttle butterfly assembly and carefully pull it clear of the machine, noting exactly how it is routed; note particularly that the cable is routed over the top of the air filter top half/plenum chamber connecting hose. Removing the handlebar cover, if necessary, first withdraw the single screw clamping the right-hand switch cluster to the twistgrip assembly, then remove its single retaining screw and withdraw the twistgrip top cover, noting how its protruding tang locates with the twistgrip drum. Disconnect the cable end nipple from the slot in the block at the chain end, then withdraw the cable. On reassembly, grease liberally all twistgrip components, noting that the handlebar weights fitted to some models must be removed by slackening the screw which secures the expander bolt retaining system; be careful that the weight is not pushed so far against the twistgrip rubber on refitting that it drags and impairs free throttle movement. Before refitting the twistgrip top cover, align the mark on one of the twistgrip drum teeth with the line on the throttle pulley to ensure full throttle movement is available.

When refitting the throttle cable, be very careful to ensure that it is routed correctly with no kinks or sharp bends and that it does not foul or snag on any other component; check at all front fork positions. Particularly check that the outer cable does not foul the handlebar cover or any other component as it passes through the steering head area, also that there is a straight run from the outer cable stop on the throttle butterfly assembly to the cable pulley; it may be necessary to renew the stop, if this is bent out of true. Open the throttle and check that it snaps quickly and easily shut at all handlebar positions. On some 1983 - 85 100 models (an authorized BMW dealer wilt have full details of the machines that may be affected) an additional earth wire should have been installed between the twistgrip/brake master cylinder assembly and the main frame earth point on the left-hand side of the frame top tube bracing gusset, to the rear of the steering head. lf this wire is not installed and the stop lamp front switch should develop a short-circuit, since the handlebars are rubber-mounted and therefore insulated from the rest of the machine, the switch may earth through the throttle cable inner wire, causing it to heat up and drag on the outer cable. If in any doubt about the throttle operation, have the machine checked by an authorized BMW dealer.

To remove the choke (fast idle) control cable slacken its locknut and unscrew the cable adjuster at its lower end, then release the cable end nipple from the butterfly operating linkage. At the handlebar end, rise off the black plastic cap and unscrew the large retaining screw to dismantle the lever. Note how the lever detent spring is fitted.

Check all lever pivot components for wear, renewing any that are damaged or worn and grease them thoroughly on refitting. Check the control cable inner wires for signs of fraying, poorly-soldered nipples and other damage, and the cable outers for signs of chafing, damaged or broken covers, or frayed or damaged ends. If any cable appears to be damaged or worn, or if it is stiff and jerky in operation, it must be renewed immediately. All the cable inner wires are; lined with nylon or a similar material which must not be lubricated with oil. If the cables become stiff through old age, wear, or damage, they must be renewed, although in some cases the application of one of the modern 'dry' lubricants may help. Finish off control lubrication by applying a few drops of engine oil or light machine oil to all nipples and control pivots, and all adjuster threads. Apply WD40 or CRC5-56 to all locks and switches. Working as described in the relevant Section of Chapters 2 - Clutch, Chapter 7 - Frame & Forks and Chapter 9- Wheels & Brakes, dismantle, clean and grease at regular intervals the stand pivots, the clutch release mechanism and the brake operating linkages. Check also the footrests and all return springs for security and correct operation.