Note: If an engine failure occurs, the oil tank and oil lines must be cleaned with the material used for this purpose in the workshop, and then blown through with compressed air.
Preparatory work
Remove left, right and centre covers. See Group 46.
Remove the battery. See Group 61.
Drain coolant. See Group 00.
Drain the engine oil from the oil tank.
Remove engine guard. See Group 46.
Remove the starter motor. See Group 12.
Remove exhaust manifold and oxygen sensor. See Group 18.
Expose the radiator. See Group 00.
Remove the intake air duct. See Group 13.
Remove intake air silencer. See Group 13.
Remove the battery box.
Remove circlip securing throttle cable to throttle flap stub and disengage the throttle cable from the guide.
Disengage throttle cable from adapter.
Disconnect plugs at throttle flap stub.
Remove the intake pipe from the cylinder head and lay it carefully to one side, complete with the throttle flap stub.
Slacken the fastener securing the lid of the electronic equipment box.
Disengage the cover from the anchorages on the main frame on each side and remove.
Disconnect the starter coil at the plug.
Remove the fastener securing the ignition-coil bracket and remove the ignition coil complete with bracket.
Remove fastener for oil lines (2) from the cylinder head.
User pliers, BMW # 17 5 500, to open the clamp securing the breather hose at the valve cover.
Remove valve cover (1).
Remove spark plug.
Remove centre screw plug on right in engine block.
Note: TDC position: Marks on the timing-chain sprockets are parallel with the cylinder head, the bores in the timing-chain sprockets are at the top.
Turn crankshaft to top dead centre position with an Allen key.
Note: Watch out for escaping oil and catch it in a suitable container.
Remove screw (3) close to the oil feed stub pipe and install locking screw, BMW # 11 6 570, to prevent the crankshaft from turning.
Removing camshafts
Remove the cable cover from the right-hand side of the cylinder.
Remove the retainer of the spring-strut adjusting knob from the frame.
Disconnect plug of oil-pressure switch.
Raise the rear frame. See Group 46.
Disconnect the oil feed line (arrow) from the engine.
Disconnect the oil feed hose from the oil tank.
Remove the oil feed line from the ABS modulator frame and push it to the right.
Remove the chain tensioner.
Remove chain guide (1).
Remove upper section of camshaft carrier (2).
Remove camshafts with chain sprockets.
Secure timing chain with retaining wire.
Remove front chain guide rail (3).
Removing cylinder head
Remove lower section of camshaft carrier.
Remove screws securing cylinder head to frame (arrow).
Use pin wrench, BMW # 116661,to slacken the locknut.
Note: Note washers.
Back off the adjuster sleeves.
Disconnect the coolant hose from cylinder head (4) and drain the last of the coolant from the radiator.
Disconnect the plug for temperature sensor (5).
Remove machine screws for chaincase (1).
Disconnect plug of oil-pressure sensor.
Remove oil pressure switch.
Remove rear collar screw (2) from cylinder head.
Remove front collar screws from cylinder head.
Remove top collar screws from cylinder head.
Remove collar nuts from cylinder head.
Raise cylinder head clear of stud bolts, turn the cylinder head and lift it toward the rear to remove.
Installation is the reverse of the removal procedure: pay particular attention to the following.
Note: Replace cylinder head gasket.
Initially tighten the collar nuts of the cylinder head to 20 Nm (3-6) and then tighten to 60 Nm (7-10).
Tighten the fasteners of the cylinder head to cylinder in the sequence as shown (11-16) to specified torque.
When looping the timing chain over the camshaft sprockets, make sure that the sprockets are at the TDC position.
Before installing the cylinder head cover, remove all traces of the gasket and clean the sealing face with degreasing agent. Also clean the groove and the seating faces for the gasket.
Tightening torques:
- Engine guard to frame: 9 Nm
- Footrest plate to frame: 30 Nm
- Silencer to exhaust manifold: 55 Nm
- Exhaust manifold to cylinder head: 20 Nm
- Intake air silencer to frame: 9 Nm
- Intake pipe to cylinder head: 21 Nm
- Lid of electronic equipment box to frame: 4 Nm
- Ignition coil holder: 9 Nm
- Oil lines to cylinder head: 8 Nm
- Cylinder head cover to cylinder head: 10 Nm
- Spark plug in cylinder head: 20 Nm
- Rear frame to main frame: 21 Nm
- Oil line to engine block: 35 Nm
- Timing-chain tensioner to cylinder head: 40 Nm
- Chain guide to bearing cap (clean threads + Loctite 243): 10 Nm
- Camshaft bearing cap to cylinder head: 10 Nm
- Cylinder head to frame: 41 Nm
- Cylinder head to frame adjusting sleeve zero play max: 5 Nm
- Cylinder head to frame locknut: 100 Nm
- Machine screws, chaincase: 10 Nm
- Collar screws, cylinder head: 33 Nm
- Collar nuts, cylinder head, stage 1: 20 Nm
- Collar nuts, cylinder head, stage 2: 60 Nm
- Starter to clutch housing: 10 Nm
- Oil-pressure switch in engine block (clean threads + Loctite 243): 12 Nm
- Cable cover to engine: 5 Nm