Knocking or pinking

□ Carbon build-up in combustion chamber. Use of a fuel additive
that will dissolve the adhesive bonding the carbon particles to the
crown and chamber is the easiest way to remove the build-up.
Otherwise, the cylinder head will have to be removed and
decarbonised (Chapter 2).

L Incorrect or poor quality fuel. Old or improper grades of fuel can cause detonation. This causes the piston to rattle, thus the knocking or pinking sound. Drain old fuel and always use the recommended fuel grade.

□ Spark plug heat range incorrect. Uncontrolled detonation indicates the plug heat range is too hot. The plug in effect becomes a glow plug, raising cylinder temperatures. Install the proper heat range plug (Chapter 1).

□ Improper air/fuel mixture. This will cause the cylinders to run hot, which leads to detonation. Clogged jets or an air leak can cause this Imbalance. See Chapter 4.

Miscellaneous causes

^_] Throttle valve doesn't open fully. Adjust the throttle grip freeplay (Chapter 1).

□ Clutch slipping. May be caused by loose or worn clutch components. Refer to Chapter 2 for clutch overhaul procedures.

□ Timing not advancing. Check ignition timing (Chapter 5).

□ Engine oil viscosity too high. Using a heavier oil than the one recommended in Chapter 1 can damage the oil pump or lubrication system and cause drag on the engine.

□ Brakes dragging. Usually caused by debris whicn has entered the brake piston seals, or from a warped disc or bent axle. Repair as necessary.

Fault Finding ref.39

4 Overheating

Engine overheats

□ Coolant level low. Check and add coolant (Chapter 1).

I ] Leak in cooling system. Check cooling system hoses and radiator for leaks and other damage. Repair or replace parts as necessary (Chapter 3).

□ Thermostat sticking open or closed. Check and replace as
described in Chapter 3.

G Faulty cooling system pressure cap. Remove the cap and have it

pressure tested. G Coolant passages clogged. Have the entire system drained and

flushed, then refill with fresh coolant.

□ Water pump defective. Remove the pump and check the components (Chapter 3).

□ Clogged radiator fins. Clean them by blowing compressed air through the fins from the back.

D Cooling fan or fan switch fault (Chapter 3).

Firing incorrect

□ Spark plugs fouled, defective or worn out. See Chapter 1 for spark
plug maintenance.

G Incorrect spark plugs.

_| Ignition control unit defective. See Chapter 5.

G Faulty ignition HT coils (Chapter 5),

Fuel/air mixture incorrect

] Main jet or fuel injector clogged or wrong size. Dirt, water or other contaminants can clog them. Clean the fuel strainer and/or filter, and the carburettors or injectors (Chapter 4). The standard jetting is for sea level atmospheric pressure and oxygen content.

G Air filter clogged, poorly sealed, or missing (Chapter 1).

G Air filter housing poorly sealed. Look for cracks, holes or loose clamps, and replace or repair defective parts. Fuel level too high or too low. Check the float height (Chapter 4).

I I Fuel tank breather hose obstructed.

G Carburettor intake manifolds loose. Check for cracks, breaks, tears or loose clamps. Replace the rubber intake manifolds if they are split or perished (Chapter 4).

Date: 2016-01-14; view: 764