Benelli TNT125 Service Manual

 Cylinder head is not tight;
 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)
 Camshaft and cam wear
 It continues to run after cutting off main switch:
 Main switch fault;
 Engine flameout switch fault;
 Fuel injector fault;
 The battery negative (-) or engine control unit
(ECU) grounding wire is loosened;
 There is carbon deposition at the valve seat;

The engine is overheated.
Others:
 Engine control unit (ECU) fails;
 Throttle body negative pressure imbalance;
 Oil viscosity is too high;
 Drive system fault;
 Brake dragging;
 Clutch is slipping
 Engine is overheated
 Suction valve fault;
 Secondary air compensating valve fault.
Motorcycle cannot run properly or do not have sufficient power at high speed:
Ignition is abnormal:
 Spark plug is dirty, damaged or abnormal;
 Spark plug is not applicable;
 Short circuit or poor contact of high voltage
package;
 High-voltage package fault;

Engine control unit (ECU) fails.
There is problem with fuel / air mixture:
 Air filter is blocked, the sealing is poor or there is
no air filter;
 Ventilation pipe fixer is loosened;
 There is water or foreign matter in the fuel;
 Throttle body assembly fixer is loosened;
 Insufficient oil supply to fuel injector;
 Air tank airway is blocked;
 Fuel pipe is blocked;
 Fuel pump fails.
Cylinder pressure is too low:

Spark plug is loosened;
 Cylinder head is not tight;
 There is no valve clearance;
 Cylinder and piston is worn;

Piston rings are damaged (worn, weak, damaged
or stuck);
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Benelli TNT125 Specifications

General

Displacement	125 cc
Transmission	5-speed
Fuel System	EFI
Fuel Capacity	7.2 liters
Seat Height	780 mm
Dry Weight	116 kg
Bore x Stroke	54 mm x 54.5 mm
Starting System	Electric
Wheelbase	1215 mm
Engine Type	Single cylinder, 4-stroke, air-cooled
Front Suspension	Upside-down fork
Front Brake	Single disc
Rear Brake	Single disc
Front Tire	120/70-12
Rear Tire	130/70-12
Max Power	8.2 kW (11.1 Cv) @ 9500 rpm
Rear Suspension	Swing arm with lateral shock absorber with adjustable spring preload