Book Excerpt: Motorcycle Maintenance Techbook: Servicing and Minor Repairs for all Motorcycles and Scooters ENGINE
ENGINE TOP-END STRIP DOWN
- Slacken the cylinder head bolts/nuts evenly in a diagonal sequence by about 1/2 a turn at a time. When all are slackened undo and remove each one. If the sequence is not followed, there is a possibility of distorting the cylinder head. On the liquid-cooled engine photographed, the bolts marked "X" do not need to be undone. The one on the right is a coolant bleed screw whereas the one on the left holds the thermostat cover in place. An air-cooled engine will have a much more obvious arrangement of cylinder head bolts/nuts.
- The cylinder head can now be lifted from the engine. If it doesn't, a gentle tap, on the side of the head with a rubber mallet will dislodge it. If it is still unwilling to move, check that you have not overlooked a bolt. Remove the cylinder head gasket from the top of the barrel.
- Slacken the reed valve block bolts by about one turn before undoing and removing them all. On the reed valve block photographed, the bolt on the far right holds the oil pump cable support bracket; take note of the bracket position so that it can be refitted correctly. Similarly take note of any washers; there should be flat washers under each bolt head or flanged bolt heads (far right bolt) should be used.
- The fiber reed valve unit shown uses four petals; others may have only two petals and may be of fiber or steel construction. Clean any old gasket from the unit and clean the petals with a soft cloth or kitchen paper. The reeds are delicate and will be damaged if compressed air is used to clean them.
- Remove the rotor cover and turn the rotor (in the normal direction of rotation) until the piston is at the top of its stroke and the piston crown level is level with the top of the barrel.
REAR SUSPENSION MAINTENANCE
TWIN SHOCK REAR SUSPENSION UNITS Each unit should be removed (in turn) and the pivot points greased once a year.
- Undo the nuts/bolts that secure one suspension unit then remove it.
- Clean and grease the pivot points and inspect the rubber bush in the eyelet(s). Some machines have bushes in both the top and bottom eyelets, other types have a bush in the top eyelet only. If the bushes have deteriorated then it is probable that the suspension unit will also have failed, although new rubber bushes can usually be purchased separately. Note that suspension units must always be replaced as a pair, never singly.
Subject: Motorcycle Maintenance Techbook. Service, maintenance and minor repairs. ISBN-10: 1785210475 | ISBN-13: 9781785210471 | Haynes 4071
Buying up a toolkit | Spanners, sockets and screwdrivers | Drifts, chisels and hammers | Pliers and other gripping devices | Measuring tools | Torque wrenches | Electrical testers and equipment.
SERVICE SCHEDULE and RECORDS
Service data | Checklist and records | Service schedule | Order of service | Chassis nuts and bolts tightening.
Engine cycles | Valve clearance check | Air filters | Liquid cooling system | Fuel system | Oil and oil filters | Clutch adjustment | Two-stroke engine top-end overhaul | Spark plug | Contact breaker points and ignition timing | Engine compression test | Exhaust system.
Chain checks and wheel alignment | Chain and sprockets replacement | Steering head, wheel and swinging arm bearing checks | Wheel bearing replacement | Gear lever, brake pedal and footrests | Handlebars, levers and cable lubrication | Front suspension maintenance | Suspension checks and adjustments | Rear suspension maintenance | Tires and tire changing | Speedometer cable and drive | Disc (hydraulic) brakes | Drum brakes | Stands | Bodywork.
Battery safety warnings | Conventional battery | Maintenance-free battery | Charging voltage test | Battery charging | Bulb changing | Horn | Handlebar switchgear | Fuses | Crimping cable connectors | Cable sizes | Soldering.
MODIFICATIONS and ACCESSORIES
Twin horn conversion | Fitting fork gaiters | Fitting a top box | Fitting and automatic drive chain oiler.