Trouble | Symptom and possible causes | Remedy |
Engine does not start or is difficult to start | Low compression | |
Cylinder or piston rings exceedingly worn. | Replace. | |
Piston ring sticking in its groove. | Repair or replace. | |
Crankcase, cylinder or cylinder head gasket leaking. | Repair or replace. | |
Loose spark plug. | Tighten | |
Piston broken, cracked or damaged. | Replace. | |
Crankshaft seal worn. | Replace. | |
No spark | ||
Foul spark plug. | Replace. | |
Wet spark plug. | Clean and dry | |
Defective coil. | Replace. | |
High-tension cable interrupted or shorted. | Replace. | |
Ignition system fault. | Repair or replace. | |
Carburetor is receiving no fuel | ||
Breather hole in filler cap clogged. | Clean. | |
Fuel cock clogged or defective. | Clean or replace. | |
Carburetor needle valve defective. | Replace. | |
Fuel tube obstructed. | Clean. | |
Foul spark plug. | Clean | |
Ignition system fault. | Repair or replace. | |
Fuel tube obstructed. | Replace. | |
Carburetor jets obstructed. | Clean. | |
Engine is burning oil | Oil pump out of adjustment. | Adjust. |
Crankshaft seal damaged or worn. | Replace. | |
Loss of engine power | Piston rings or cylinder worn. | Replace. |
Incorrect air gap between spark plug electrodes or ignition system faulty. | Adjust or replace. | |
Carburetor jets obstructed. | Clean. | |
Incorrect fuel level in carburetor float chamber. | Adjust. | |
Air cleaner clogged. | Clean. | |
Air leaking past the intake duct. | Tighten or replace. | |
Engine is receiving too much oil. | Adjust the oil pump. | |
Engine overheats | Too much carbon build-up on piston crown. | Clean. |
Engine is receiving insufficient oil. | Adjust the oil pump. | |
Oil pump faulty or oilways obstructed. | Replace or clean. | |
Fuel level in carburetor float chamber too low. | Adjust. | |
Air leaking into intake duct. | Tighten or replace. | |
Engine oil used does not meet specification. | Use specified oil. | |
Cooling system faulty. | Read radiator section. |