Abnormal Running During Low-Speed Driving; Abnormal Running Or Poor Power During High-Speed Driving - Benelli TNT 25 Maintenance Manual

Abnormal running during low-speed
driving:
Spark is weak:
Battery voltage is low;
Alarming system fault;
Ignition coil fault;
Short circuit or poor contact of ignition coil;
Spark plug is dirty, damaged or clearance is abnormal;
Spark plug is unsuitable;
Engine control unit (ECU) fault;
Camshaft position sensor fault;
Crankshaft sensor fault
Abnormal fuel / air mixture:
Bypass screw is poor adjusted;
Airway is blocked;
Exhaust pipe and exhaust vent is blocked;
Idle air channel is blocked;
Air filter is blocked, leaky or not installed;
Fuel tank vent is blocked;
Fuel pump fault;
Throttle body assembly fixer is loosened;
Vent pipe fixer is loosened
Cylinder pressure is too low:
Spark plug is loosened;
Cylinder head is not tightened;
There is no valve clearance;
Cylinder and piston is worn;
Piston rings are damaged (worn, weak, damaged or stuck);
The gap between the piston ring and the piston ring groove
is too large;
Cylinder head gasket is damaged;
Cylinder head is deformed;
Valve spring is damage or the elasticity is poor;
Valve is not installed properly (valve is bent or worn or there
Abnormal running or poor power
during high-speed driving:
Ignition is abnormal:
Spark plug is dirty, damaged or abnormal;
Spark plug is unsuitable;
Short circuit or poor contact of ignition coil ;
Ignition coil fault
Engine control unit (ECU) fault
Abnormal fuel / air mixture:
Air filter is blocked, the sealing is poor or there is no air
filter;
Breathe hose fixer is loosened;
There is water or foreign matter in the fuel;
Throttle body assembly fixer is loosened;
Insufficient fuel supply to fuel injector;
Fuel tank airway is blocked;
Fuel hoseis blocked;
Fuel pump fault;
Cylinder pressure is too low:
Spark plug is loosened;
Cylinder head is not tightened;
There is no valve clearance;
Cylinder and piston is worn;
Piston rings are damaged (worn, weak, damaged or stuck);
The gap between the piston ring and the piston ring groove
is too large;
Cylinder head gasket is damaged;
Cylinder head is deformed;
Valve spring is damage or the elasticity is poor;
Valve is not installed properly (valve is bent or worn or there
is carbon deposition at valve seat)
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