Benelli TNT125 Service Manual

Troubleshooting Guide
Remark
○For most of EFI faults, see the chapter “EFI”.
○This table is not exhaustive and it is unable to list the
possible causes of each issue and can only be used as a
basic guide to help solve some common problems.
The engine cannot start or is difficult to start:
Starter motor does not run:
 The main switch or the engine flameout switch is
not turned on;
 Starter locking switch or gear switch fault;
 Starter motor fault;
 Battery voltage is low;
 Starter relay contact is not good or cannot work
properly;
 Start button contact is not good;
 Short circuit or open circuit of starting system;
 Main switch fault;
 Engine flameout switch fault;

Main fuse or main switch fuse blows out.
Starter motor is running, but the engine does not run:
 Motorcycle rollover sensor (EFI) is actuated;
 Anti-theft control system fault;
 Overrun clutch fault;
 Starting idler fault.
Engine does not run:
 Valve is seized;
 Valve mandrel is seized;
 Cylinder and piston is seized;
 Crankshaft is seized;
 Small end of connecting rod is seized;
 Big end of connecting rod is seized;
 Transmission gear or bearing is seized;
 Camshaft is seized;
 Starting idler is seized;

Balanced shaft bearings is seized.
There is no fuel flow:
 There is no fuel in the tank;
 Fuel pump fails;
 Vent hole of fuel tank is blocked;
 Fuel filter is blocked;

Fuel pipe is blocked.
There is no spark; spark is weak:
 Motorcycle rollover sensor (EFI) falls off;
 The main switch is not rotated to “On”;
 The engine flameout switch is not rotated to “Off”;
 Not grasp the clutch handle or gear is not at
neutral position;
 Battery voltage is low;
 Anti-theft control system fault;
 Spark plug is dirty, damaged or electrode
clearance is abnormal;
 Spark plug is not applicable;
 Short circuit or poor contact of high voltage
package;
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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