Malfunction | Fault definition | Cause of malfunction | Remedy |
Engine won't start | Using a multimeter, check the resistance of the ignition coil | Faulty ignition coil | Replace ignition coil |
Using a multimeter, check the resistance of the high-voltage wires and the voltage at the contacts of the primary circuit of the ignition coil | The high-voltage wires of the ignition system are broken or burnt out, the low-voltage wires are broken | Replace high voltage wires, repair low voltage wire breaks | |
Check the position of the emergency stop switch | Emergency stop switch turned off | Turn on the emergency stop switch | |
Check the presence of fuel in the tank, check the integrity of the fuel and vacuum hoses, check the condition of the fuel filter and carburetors | Fuel does not enter the cylinders | Fill the tank with fuel, change the fuel filter if necessary and flush the carburetors | |
Check the condition of all sensors responsible for blocking the engine start: neutral sensor, side stop sensor, clutch lever sensor | Any gear other than neutral is engaged, the side stop is not removed, the sensor wires are broken, or the sensors are faulty | Engage neutral gear, check the condition of the sensors and wires. replace if necessary | |
Check the engine control unit | Faulty engine control unit | Replace Block | |
The engine runs unevenly or intermittently | Check the power system, flush the carburetors | The engine runs on a lean mixture: fuel is poorly supplied to the carburetor, the carburetor jets are dirty | Adjust carburetors, flush fuel cock, change fuel filter, flush carburetors |
Faulty spark plugs, broken spark plug gaps | Interruptions in sparking | Replace spark plugs or set recommended gap between spark plug electrodes | |
Engine smokes a lot (black smoke), when the engine is running, pops are heard in the carburetors, gasoline flows from the carburetors | The engine runs on a rich mixture: the needle valve of the carburetor is faulty | Check carburetor needle valve, repair carburetor | |
There is no synchronization in the operation of the cylinders | Wrong carburetor adjustment | Adjust carburetors | |
Weak compression, there are traces of oil on the electrodes of the candles | Piston rings coked or worn, valves loose on seats | Engine repair needed | |
Check for dirty carburetors | Clogged idle jets in carburetors | Clean the idle jets of the carburetors | |
The engine does not develop full power | Check carburetor adjustment | Incorrectly adjusted or out of sync carburetors | It is necessary to adjust the carburetors and the synchronism of their work |
Check valve clearances | Valve clearances incorrectly adjusted | Adjust valve clearances | |
The engine runs well at high speeds, stalls at low | Weak compression | Valves not tight to seats | Engine repair needed |
Weak compression, traces of oil are visible on the electrodes of the candles | Clogged or worn piston rings | Engine repair needed | |
Heavily worn cylinders and/or pistons | Engine repair needed | ||
The engine gets very hot | Engine slowly increases idle speed | Overfilling of carburetor float chambers due to faulty needle valves | Power system needs to be repaired |
The air filter element needs to be visually inspected | Air filter dirty | Replace the air filter | |
The engine slowly increases the speed, pops are heard in the carburetors | Engine running lean | Adjust carburetors, check planes of connection of carburetors with cylinder heads and eliminate air leakage | |
High oil consumption in the engine | Engine smokes while running (gray smoke), there are traces of oil on the electrodes of the candles | Clogged or worn piston rings | Engine repair needed |
Visible smoke from the breather channel, the engine smokes during operation (gray smoke), there are traces of oil on the electrodes of the candles | Worn pistons and/or cylinders | Engine repair needed | |
Oil leaks from under the landing planes of the cylinder block and cylinder head | Loosely tightened cylinder head fasteners, damaged gaskets | It is necessary to tighten the connections to the regulated torque or replace the gaskets |