Description
Benelli TRK 251 BJ250-18 Service Manual
This is the complete workshop service manual for the Benelli TRK 251, covering the BJ250-18 model in its China, European regulation, and non-European regulation variants. Whether you are performing routine maintenance, diagnosing an EFI fault, rebuilding the top end, or tracing an electrical gremlin through the wiring harness, this manual provides the procedures, specifications, and exploded views needed to get the job done correctly. It is the same type of document a professional technician would use in a well-equipped workshop.
File Details
- Manual type: Motorcycle Maintenance / Service Manual
- Brand: Benelli
- Model: TRK 251 (BJ250-18)
- Language: English
- Page count: Approximately 490 pages
- File format: PDF
- Coverage: China, European regulation, and non-European regulation models
Chapters Covered
- Introduction and Important Notices
- Chapter I — Basic Information
- Maintenance instructions
- Battery installation
- Sharp edge and solvent safety
- Cleaning, sorting, and storing removed parts
- Fastening sequence and locking torque
- Gaskets, O-rings, liquid gasket, and locking agent
- Press fitting, bearings, oil seals, circlips
- Lubrication, engine rotation direction, wiring
- Cable arrangement and tools
- Model information and basic specifications
- General technical parameters and unit conversion table
- Chapter II — Regular Maintenance
- Regular maintenance table
- Torque and locking agent specifications
- EFI — throttle control, idle speed, fuel hose, vapor recovery
- Cooling system — coolant level, radiator pipes
- Engine cylinder head and valve clearance
- Clutch — control system and free stroke
- Wheel/tire — pressure, wear, bearings
- Final drive — chain lubrication, slack, alignment, wear
- Brake — hoses, free stroke, fluid level, pad wear, brake light
- Suspension — front fork, rear shock absorber
- Steering — clearance, adjustment, bearing lubrication
- Electrical — lights, switches, headlight accuracy, sidestand switch
- Frame lubrication and fastener tightness
- Replacement procedures — air filter, fuel hose, coolant, radiator hose, oil, brake hose, brake fluid, master cylinder rubber, caliper rubber, spark plug
- Chapter III — Electronic Fuel Injection (EFI)
- EFI system introduction and component positions
- Technical parameters
- Fuel tank — exploded view, disassembly, inspection, installation
- Fuel vapor recovery system
- Precautions for EFI overhaul
- ECU — engine controller MT05, appearance, disassembly, installation
- Fuel pump — working principle, disassembly, inspection, installation
- Throttle body — working principle, sensors, cleaning, installation
- Fuel injector — operation, seals, installation, replacement
- Engine water temperature sensor
- Intake temperature sensor
- Inlet pressure sensor
- Oxygen sensor
- Idle speed stepper motor
- Canister solenoid valve (ECP)
- Fault maintenance and diagnosis — fault lamp, diagnostic apparatus, PCHUD software, fault code table
- Common troubleshooting methods
- Daily use and maintenance
- Chapter IV — Cooling System
- Exploded view of cooling system and water pump
- Coolant flow diagram
- Technical parameters
- Coolant — deterioration check, level check, draining, adding, pressure test, flushing
- Coolant reserve tank disassembly/installation
- Water pump — disassembly, installation, impeller inspection
- Radiator — disassembly/installation, fan, inspection, cap inspection, filler inspection
- Thermostat — disassembly, installation, inspection
- Hose and pipeline — installation, inspection
- Water temperature sensor — disassembly, installation, inspection
Complete PDF Bookmark Tree
Complete Bookmarks
The complete bookmarks in the “Benelli TRK 251 BJ250-18 Service Manual – Complete Workshop Repair Guide” are as follows:
Exhaust Emission Control Informationp. 3
It is strictly forbidden to modify the noise contrp. 5
Prefacep. 23
+Chapter I Basic Informationp. 23
+Maintenance instructionsp. 24
Installation of Batteryp. 25
Sharp edge of partp. 25
Vehiclep. 25
Cleaning the motorcycle before disassemblyp. 26
Sort out and clean the removed partsp. 26
Store the removed partsp. 26
Checkp. 26
Replacement partp. 27
Assembly sequencep. 27
Fastening sequencep. 27
Locking torquep. 27
Forcep. 28
Gasket, O-ringp. 28
Liquid gasket, locking agentp. 28
Press fittingp. 28
Ball bearing and needle bearingp. 29
Oil seal, grease sealp. 29
Circlip, cotter pinp. 29
Lubricationp. 30
Engine rotation directionp. 30
Wirep. 30
+Cable connector checkp. 30
1. Disconnectp. 31
2. Checkp. 31
3. Checkp. 31
4. Checkp. 31
5. Checkp. 32
Cable arrangementp. 32
Toolsp. 33
+Model informationp. 33
Chinap. 34
Europep. 34
Non-Europeanp. 35
Important recognitionp. 36
Basic specificationsp. 37
General Technical Parametersp. 38
Unit conversion tablep. 42
+Chapter II Regular Maintenancep. 44
Regular maintenance tablep. 45
+Torque and locking agentp. 47
Main locking torque specificationsp. 48
Locking torque and related parameters of nuts, bp. 51
Technical parametersp. 53
+Regular maintenance proceduresp. 55
+Fuel Injection System (EFI)p. 56
Check throttle control systemp. 56
Check fuel hose (fuel leak, hose rupture, hose insp. 57
Check fuel vapor recovery system (models in China,p. 58
+Cooling Systemp. 60
Inspection of cooling fluid levelp. 60
Check radiator pipes (coolant leakage, radiator pip. 60
+Engine cylinder head and cylinder head coverp. 61
Checking valve clearance;p. 61
Adjusting the valve clearancep. 62
Check whether the air inlet unit has been damagedp. 66
+Clutchp. 67
Check if the clutch control system is normalp. 67
Check the free stroke of clutch handlep. 67
+Wheel/tirep. 67
Check the tire pressurep. 68
Check wheel / tire for wearp. 68
Check the wear of treadp. 68
Check whether the wheel bearing has been damagedp. 69
+Final Drive Mechanismp. 69
Check the lubrication state of drive chainp. 70
Check whether the drive chain is slackp. 70
Adjust drive chain slacknessp. 70
Check wheel alignmentp. 72
Check the wear of drive chainp. 72
Check the wear of chain guidep. 73
+Brakep. 73
Check brake hoses and brake lines for damage and ep. 74
Free stroke of front brakep. 74
Free stroke of rear brakep. 74
Inspection of brakep. 75
Inspection of brake fluid levelp. 75
Inspection of wear of brake padp. 76
Inspection of brake light switchp. 77
Check the output voltage of speed sensorp. 77
+Suspension system:p. 79
Check front fork / rear shock absorberp. 79
Check the front fork shock absorber for oil leakagp. 79
Check the rear shock absorber for oil leakagep. 80
+Steering systemp. 80
Check steering clearancep. 81
Adjust the steering seat properlyp. 81
Lubricate steering stem bearingsp. 82
+Electrical Systemp. 82
+Check lights and switchesp. 83
Step Ip. 83
Step IIp. 84
Step IIIp. 84
+Check the headlight accuracyp. 86
Adjustment of headlight beamp. 87
Check the sidestand flameout switchp. 87
+Check emergency stop switchp. 89
+Othersp. 89
+Lubricate frame partsp. 90
Pivot shaft: lubricate it with greasep. 90
Wire: lubricate it with greasep. 90
Cable: lubricate it with greasep. 90
+Check the tightness of bolts, nuts and fastenersp. 91
Bolts, nuts and fasteners to be checkedp. 91
+Replacement partp. 92
Replace of air filter elementp. 93
Replacement of fuel hosep. 95
Replacement of coolantp. 96
Replacement of radiator hosep. 99
Replace oilp. 100
Replacement of brake hosep. 101
Replacement of rear brake hosep. 103
Replacement of brake fluidp. 104
+Replacement of rubber parts of master cylinderp. 107
Disassemble front master cylinderp. 108
Disassembly of rear master cylinderp. 108
Assembly of master cylinderp. 109
+Replacement of rubber parts of caliperp. 109
Disassembly of front caliperp. 110
Assembly of front caliperp. 110
Disassembly of rear caliperp. 111
Assembly of rear caliperp. 112
Replace spark plugp. 114
+Chapter III Fuel Injection System (EFI)p. 115
Introduction to EFIp. 117
EFI systemp. 118
EFI part positionp. 120
Technical parametersp. 127
+Fuel tankp. 130
Exploded view of fuel tankp. 130
Fuel vapor recovery systemp. 131
+Fuel tankp. 133
Disassemble fuel tankp. 133
Check the fuel tankp. 134
Install the fuel tankp. 134
+Precautions for EFI overhaulp. 134
Precautions for EFI overhaulp. 135
+ECUp. 136
Engine controller (MT05 ECU)p. 137
ECU appearancep. 137
ECU disassemblyp. 137
ECU installationp. 137
Precautions for ECUp. 137
ECU Power Supply Requirementsp. 138
ECU temperature requirementsp. 138
+fuel pumpp. 138
Working principle of fuel pumpp. 139
Appearance of fuel pump:p. 139
Fuel pump compositionp. 140
Fuel pump label and logop. 140
Working environment of fuel pumpp. 140
+Maintenance process of fuel pump:p. 141
Safety Protection:p. 141
Fault diagnosis of fuel pump assembly:p. 142
Disassembly of fuel pump assembly:p. 142
Installation of fuel pump assembly:p. 142
Fuel pressure release process:p. 143
Fuel leakage check process:p. 143
Notes for Use:p. 143
+Throttle Bodyp. 144
Working Principle of Throttle Body:p. 145
Appearance of Throttle Body:p. 145
+Technical parametersp. 145
Throttle Body:p. 146
Throttle position sensor:p. 146
Idle air control valve:p. 146
Operating temperature of throttlep. 146
Disassemble throttle bodyp. 146
Cleaning Method of Throttlep. 146
install throttle bodyp. 146
Notes for the Installation of Throttle Bodyp. 147
Notes for the Use of Throttle Bodyp. 147
+Fuel injectorp. 148
Working Principle of Fuel Injector:p. 148
Appearance of fuel injectorp. 148
+Fuel injector sealp. 148
O-ring Seal Connected to Oil Rail or Oil Injectionp. 149
O-ring Seal Connected to Intake Pipe Endp. 149
List of recommended lubricantsp. 149
Overvoltage Impact of fuel injectorp. 149
Temperature range of fuel injector:p. 149
Fuel contaminants of fuel injectorp. 150
Fuel injector harness arrangementp. 150
Notes for Use of Fuel Injectorp. 150
Installation requirements for fuel injectorp. 151
Replacement Method of Fuel Injectorp. 151
Replaceability of fuel injectorp. 152
Blocking of Fuel Injectorp. 152
+Engine water temperature sensorp. 152
Working principles of engine water temperature senp. 153
Appearance of engine water temperature sensorp. 153
Installation requirements for engine water temperap. 153
Operating environment of engine water temperaturep. 153
Electrical environment of engine water temperaturep. 153
Cleaning of engine water temperature sensorp. 154
+Inlet temperature sensorp. 154
Working principle of intake temperature sensorp. 155
Appearance of intake temperature sensorp. 155
Technical parametersp. 155
Pin position definition and function diagramp. 156
Installation position of intake temperature sensorp. 156
Cleanp. 156
+Inlet pressure sensorp. 156
Working principles of inlet pressure sensorp. 157
Appearance of inlet pressure sensorp. 157
Operating environmentp. 157
Storage environmentp. 157
Electrical environmentp. 158
Pin definitionp. 158
Locationp. 158
Cleanp. 158
+Oxygen sensorp. 159
Working principle of oxygen sensorp. 160
Appearance of oxygen sensorp. 160
Technical parametersp. 160
Installation requirementsp. 160
Oxygen sensor pin definition:p. 161
Characteristic curvep. 161
Requirements for fuel qualityp. 162
+Idle speed stepper motorp. 162
Working principle of idle speed stepper motorp. 163
Appearance of idle speed stepper motorp. 163
Pin Definitionp. 164
Characteristic parameters:p. 164
Cleanp. 164
+Canister solenoid valve (ECP)p. 164
Overview of working principlep. 165
Appearancep. 165
Pin of ECP solenoid valvep. 165
Technical parametersp. 165
Installation requirementsp. 166
+Fault Maintenance and Diagnosis Method of EFI Sysp. 166
Conduct diagnosis directly using the flashing faulp. 167
Diagnose fault using diagnostic apparatusp. 169
Check fault using diagnostic software PCHUDp. 170
+Common troubleshooting methods for electronic fuep. 176
Maintenance toolp. 177
+Engine working data flow displayed by diagnostic ap. 177
Step Ip. 177
Step IIp. 177
Step IIIp. 178
+Simple Troubleshootingp. 178
Daily Use and Maintenancep. 178
Fault phenomenon-Start Faultp. 178
Fault phenomenon—Start failure with temperingp. 180
Fault phenomenon—Instable idle speedp. 180
Fault phenomenon—Too high or too low idle speed (ip. 180
Fault phenomenon—Instable idle speed with decelerap. 180
Fault phenomenon—Insufficient power of deceleratiop. 180
Fault phenomenon—Slight burning phenomenonp. 180
Fault phenomenon—Fault lamp is on, but fault codep. 180
Fault phenomenon—Extremely high fuel consumptionp. 181
+Chapter IV Cooling Systemp. 183
Exploded view of cooling systemp. 183
Exploded view of water pumpp. 186
Coolant flow diagramp. 187
Technical parametersp. 189
+Cooling fluidp. 190
Check coolant for deteriorationp. 190
Check coolant levelp. 190
Drain the coolantp. 190
Add the coolantp. 190
Detect pressurep. 190
Flushing Cooling Systemp. 190
Disassembly/Installation of Coolant Reserve Tankp. 191
+Water pumpp. 191
Disassembly of Water Pumpp. 192
Installation of Water Pumpp. 193
Check water pump impellerp. 193
+Radiatorp. 193
Disassembly of Radiator and Radiator Fanp. 194
Assembly of Radiator and Radiator Fanp. 195
Inspection of Radiatorp. 195
Inspection of radiator coverp. 196
Inspection of Radiator Fillerp. 198
+Thermostatp. 198
Disassembly of Thermostatp. 199
Installation of Thermostatp. 200
Inspection of Thermostatp. 200
+Hose and Pipelinep. 201
Installation of Hosep. 202
Check hosep. 202
+Water temperature sensorp. 202
Disassembly / installation of water temperature sep. 203
Check water temperature sensorp. 203
+Chapter V Enginep. 204
+Lubrication Systemp. 206
Exploded view of fuel pumpp. 206
Oil flow diagramp. 208
Preparatory informationp. 208
Technical parametersp. 209
+Fuel pumpp. 210
Disassembly of fuel pumpp. 210
Inspection of Fuel Pumpp. 211
Installation of fuel pumpp. 212
+Sub-assembly of Cylinder Headp. 213
Exploded View of Cylinder Headp. 213
Exploded view of camshaft and valvep. 215
Exploded view of timing drive mechanismp. 216
Preparatory informationp. 217
Technical parametersp. 218
Special tools and sealantsp. 218
+Cylinder headp. 221
Disassembly of cylinder headp. 221
Valve decompositionp. 223
Inspection of combustion chamberp. 223
Inspection of cylinder head joint surfacep. 223
Inspection of intake and exhaust springsp. 224
Inspection of valve stemp. 224
Inspection of valve guidep. 225
Replacement of Valve Guidep. 225
Adjustment of Valve Seat Ringp. 226
Installation of Cylinder Headp. 227
+Tensionerp. 228
Function of tensionerp. 228
Disassembly of Tensionerp. 229
Assembly of Tensionerp. 229
Inspection of Tensionerp. 229
+Cylinder Block and Pistonp. 230
Exploded View of Cylinder Bodyp. 230
Exploded view of piston / crankshaftp. 231
Preparatory informationp. 232
Technical parametersp. 233
+Inspection and replacement of cylinder blockp. 234
14.3 Disassembly of Cylinder Blockp. 234
Installation of Cylinderp. 234
Check cylinder blockp. 235
+Pistonp. 235
Disassembly of Pistonp. 235
Installation of Pistonp. 236
Check the piston, piston pin and piston ringp. 237
+Crankshaft connecting rodp. 240
Exploded view of crankshaft connecting rodp. 240
Preparatory informationp. 242
Technical parametersp. 243
+13.6 Crankshaft Connecting Rod Combinationp. 244
Disassembly of Crankshaft Connecting Rod Combinatip. 244
Assemblyp. 244
Checkp. 244
+Balance shaftp. 245
Function of balancer shaftp. 245
Disassembly of balancer shaftp. 245
Assembly of balancer shaftp. 246
Inspection of balancer shaftp. 246
+Clutchp. 247
Exploded view of clutchp. 247
Special toolsp. 249
Disassembly of clutchp. 250
Disassembly of Clutchp. 252
Installation of clutchp. 253
Inspection of clutchp. 253
+Gearshift Mechanismp. 254
Exploded View of Gearshift Mechanismp. 254
Disassembly of Gearshift Mechanismp. 257
Installation of Gearshift Mechanismp. 258
Inspection of Gearshift Mechanismp. 258
Disassembly of primary / auxiliary shaft componentp. 260
Disassembly of primary / auxiliary shaft componentp. 261
Inspection of primary / auxiliary shaft componentp. 262
+Chapter VI Finished Motorcyclep. 262
+Wheel/tirep. 267
Exploded view of front wheel/tirep. 268
Exploded view of rear wheel/tirep. 268
Technical parametersp. 271
Special toolsp. 272
+Wheel (rim)p. 272
Disassemble front wheelp. 273
Install front wheelp. 274
Disassemble rear wheelp. 275
Installation of rear wheelp. 276
Check wheelp. 277
Check the axlep. 278
Adjustment of static balance of rimp. 278
Adjustment / inspection of tire pressurep. 280
Check tirep. 280
Disassemble tirep. 280
Mount tirep. 281
+Hub bearingp. 283
Disassemble hub bearingp. 284
Install hub bearingp. 284
Inspection of hub bearingp. 285
Hub bearing lubricationp. 285
+Transmission mechanismp. 286
Exploded view of drive mechanismp. 286
Technical parametersp. 288
Special toolsp. 289
+Drive chainp. 289
Check the slackness of drive chainp. 290
Inspection of slackness of drive chainp. 290
Inspection / adjustment of wheel alignmentp. 290
Inspection of wear of drive chainp. 290
Drive chain lubricationp. 290
Disassembly of drive chainp. 290
Installation of drive chainp. 291
+Sprocket, collar, collar bearingp. 292
Disassembly of rear sprocketp. 293
Installation of rear sprocketp. 293
Disassemble collar bearingp. 294
Install collar bearingp. 294
Check collar bearingp. 294
Lubricate collar bearingp. 295
Check the damper of collarp. 295
Check the wear of sprocketp. 295
Check the deformation of rear sprocketp. 295
+Brakep. 297
Exploded View of Brakep. 297
Technical parametersp. 299
Special toolsp. 300
+Brake lever, brake pedalp. 300
Adjustment of position of brake leverp. 301
Inspection of position of brake pedalp. 301
Adjustment of position of brake pedalp. 301
Disassembly of brake pedalp. 302
Installation of brake pedalp. 302
+Caliperp. 304
Disassembly of front caliperp. 304
Disassembly of rear caliperp. 304
Installation of caliperp. 304
Disassembly of front caliperp. 305
Assembly of front caliperp. 305
Diassembly of rear caliperp. 305
Assembly of rear caliperp. 305
Inspection of fluid sea of caliper for leakagep. 305
Inspection of dust seal of caliper for damagep. 305
Inspection of the caliper piston and brake cylindep. 306
+Brake padp. 306
Remove the front brake padp. 306
Installation of front brake padp. 307
Disassembly of Rear Brake Padp. 307
Installation of Rear Brake Padp. 308
Inspection of wear of brake padp. 308
+Master cylinderp. 308
Disassemble front master cylinderp. 308
Installation of front master cylinderp. 309
Disassembly of rear master cylinderp. 310
Installation of rear master cylinderp. 311
Disassembly of front master cylinderp. 311
Disassembly of rear master cylinderp. 311
Assembly of master cylinderp. 311
Check the master cylinder (visual inspection)p. 311
+Brake discp. 312
Disassembly of front brake discp. 312
Disassembly of rear brake discp. 312
Installation of brake discp. 313
Inspection of wear of brake discp. 313
Inspection of deformation of brake discp. 314
+Brake fluidp. 314
Inspection of level of brake fluidp. 314
Replacement of brake fluidp. 314
Exhaust the air inside the brake linep. 314
+Brake hosep. 315
Disassembly / installation of brake hose and brakep. 315
Inspection of Brake Hoses and Brake Linesp. 315
+Anti-lock brake system (ABS)p. 316
Part positionp. 316
ABS system circuit diagramp. 316
Pin namep. 317
+ABS overhaulp. 318
Precautions for ABS overhaulp. 319
Overview of ABS fault removalp. 320
ABS diagnostic flow chartp. 322
Carry out the pre-diagnosis inspection (Phase 1)p. 324
Carry out the pre-diagnosis inspection (Phase 2)p. 325
Overview of diagnosisp. 326
Check the ABS indicator (LED).p. 326
ABS indicator (LED) is on (rotate the ignition swip. 327
ABS indicator (LED) is on (motorcycle is driving –p. 328
The difference between front and rear wheel speedsp. 328
Wheel speed sensor is open or shorted (front: C008p. 329
Check the line of wheel speed sensor (fault code:p. 329
Relay fault (C0044-C0046)p. 329
ABS normally open valve solenoid circuit is open-cp. 329
ABS normally closed valve solenoid circuit is openp. 329
ABS voltage is too high, ABS voltage is too low (tp. 329
ABS pump or motor fault (C0070-C0074)p. 329
Intermittent signal of wheel speed sensor (front:p. 330
ABS wheel speed difference is too highp. 330
Brake diode breakdown (C0062)p. 330
Brake switch line fault (C0060-C0061)p. 330
ABS indicator light (LED) fault (C0210-C0213)p. 330
Speed output port fault (C0230-C0231)p. 330
Front wheel speed sensor signal is abnormal (faultp. 331
Rear wheel speed sensor signal is abnormal (faultp. 331
Check ECU (fault code: C0044-C0046)p. 332
+ABS hydraulic systemp. 332
Disassemble ABS hydraulic mechanismp. 332
Install ABS hydraulic mechanismp. 334
Check ABS hydraulic mechanismp. 335
+Speed sensorp. 336
Remove front wheel speed sensorp. 336
Install front wheel speed sensorp. 336
Remove rear wheel speed sensorp. 336
Install rear wheel speed sensorp. 337
Check front wheel speed sensorp. 337
Check the clearance of wheel speed sensorp. 338
Check the gear ring of wheel speed sensorp. 338
+Suspension systemp. 339
Exploded view of front suspension systemp. 340
Exploded view of rear suspension systemp. 341
Technical parametersp. 344
Special toolsp. 345
+Front Shock Absorberp. 345
Disassembly of Front Shock Absorberp. 346
Installation of Front Shock Absorberp. 346
Replacement of Front Shock Absorber Fluidp. 347
Disassembly of Front Shock Absorberp. 350
Inspection of inner tube and outer tubep. 352
Inspection of Dust Sealp. 352
Inspection of Spring Tensionp. 353
+Rear shock absorberp. 354
Adjustment of pretightening force of springp. 354
Disassembly of Rear Shock Absorberp. 355
Assembly of Rear Shock Absorberp. 356
Inspection of Rear Shock Absorberp. 356
+Rear rocker armp. 356
Disassembly of Swing Armp. 357
Installation of Swing Armp. 358
Disassembly of Swing Arm Bearingp. 358
Installation of Swing Arm Bearingp. 359
Check swing arm bearingp. 359
Check the chain guidep. 359
+Control Systemp. 359
Exploded View of Control Systemp. 360
Special toolsp. 362
+Control Systemp. 362
Inspection of Control Systemp. 363
Adjustment of Control Systemp. 363
+Handlebarp. 363
Disassembly of Handlebarp. 364
Installation of handlebarp. 365
+Steering stemp. 366
Disassembly of Steering Stem and Steering Stem Beap. 367
Installation of Steering Stem and Steering Stem Bep. 368
Lubrication of Steering Stem Bearingp. 370
Inspection of Deformation of Steering Stemp. 370
+Framep. 371
Exploded View of Framep. 371
Exploded view of left footpegp. 372
Exploded view of right footpegp. 374
Exploded View of Mufflerp. 376
Exploded View of Rack and Luggage Carrierp. 378
Exploded View of Fenderp. 381
Exploded View of Headlight Coverp. 382
Exploded View of Cowlingp. 385
Exploded View of Fuel Tank Coverp. 387
Exploded View of Seat Cushions and Coversp. 389
Exploded View of Engine Accessoriesp. 390
+Seat Cushionp. 392
Disassembly of seat cushionp. 392
Installation of seat cushionp. 392
+Coverp. 392
Disassembly of Left Coverp. 393
Installation of Left Coverp. 393
Disassembly of Right Coverp. 393
Installation of Right Coverp. 393
Disassembly of left coverp. 394
Installation of left coverp. 394
Disassembly of right coverp. 394
Installation of right coverp. 394
+Rear rack and side case bracketp. 394
Disassembly of side case bracketp. 395
Installation of side case bracketp. 395
Disassembly of rear rackp. 396
Installation of rear rackp. 397
+Side coverp. 398
Disassembly of side coverp. 398
Installation of Side Coverp. 398
+Rear fenderp. 398
Disassembly of rear fenderp. 399
Installation of rear fenderp. 399
+Front fenderp. 400
Disassembly of Front Fenderp. 400
Installation of Front Fenderp. 400
+Windshield and cowlingp. 401
Disassembly of windshieldp. 401
Disassembly of cowlingp. 402
Installation of windshield and cowlingp. 402
+Headlight cover and left and right front panelp. 403
Disassembly of headlight coverp. 403
Installation of headlight cover and left and rightp. 406
+Tank coverp. 406
Disassembly of Fuel Tank Coverp. 407
Installation of Fuel Tank Coverp. 407
+Framep. 407
Disassembly of Framep. 408
Installation of Framep. 408
Inspection of Framep. 409
+Sidestandp. 409
Disassembly of Sidestandp. 410
Installation of Sidestandp. 410
+Left Front Footpegp. 410
Disassembly of Left Front Footpegp. 411
Installation of Left Front Footpegp. 411
+Left Rear Footpegp. 412
Disassembly of Left Rear Footpegp. 413
Installation of Left Rear Footpegp. 413
+Front Right Footpegp. 413
Disassembly of Front Right Footpegp. 414
Installation of Front Right Footpegp. 414
+Rear Right Footpegp. 414
Disassembly of Rear Right Footpegp. 415
Installation of Rear Right Footpegp. 415
+Mufflerp. 416
Disassembly of mufflerp. 416
Installation of Mufflerp. 417
+Disassembly/Installation of Enginep. 417
Exploded View of Disassembly/Installation of Enginp. 418
Disassembly of Enginep. 419
Installation of Enginep. 424
+Chapter VII Electrical Systemp. 427
Precautionsp. 430
Technical parametersp. 430
Special toolp. 431
+Electrical wiringp. 432
+Charging Systemp. 433
Charging system circuit diagramp. 434
+Batteryp. 434
Disassemble batteryp. 435
Install batteryp. 435
Activation of batteryp. 436
First chargep. 437
Inspection of charging statep. 439
+Alternatorp. 441
Remove alternatorp. 441
Check the alternatorp. 442
Install the alternatorp. 442
+Voltage regulator/rectifierp. 442
Remove rectifierp. 443
Inspection of Circuit at Main Wiring Terminalp. 443
Check rectifierp. 443
Install rectifierp. 443
+Ignition Systemp. 444
Ignition system circuit diagramp. 444
Precautions for operationp. 444
+Crankshaft sensorp. 445
Remove crankshaft position sensorp. 446
Check crankshaft position sensorp. 446
+Ignition coilp. 446
Remove ignition coil:p. 447
Check ignition coilp. 447
Installation of ignition coilp. 447
+Spark plugp. 448
Inspection of spark plugp. 448
Checkp. 448
Check IC igniterp. 449
ECU unitp. 449
Ignition System Troubleshootingp. 449
+Starter Systemp. 451
Starter system circuit diagramp. 451
+Starting Motorp. 451
Remove the starter motorp. 452
Check the starter motorp. 452
Check the brushp. 452
Clean and check commutatorp. 453
Check the brush leadp. 453
Check the right end cover assemblyp. 454
Install the starter motorp. 454
Starter relayp. 454
Remove starter relayp. 455
Inspection of action of starter relayp. 455
Install starter relayp. 455
+Lighting Systemp. 455
+Headlightp. 456
Disassemble headlight relay controllerp. 456
Check headlight relay controllerp. 456
Install headlight relay controllerp. 456
Remove headlightp. 457
Replace headlight bulbp. 457
Replacement of headlight bulbp. 457
Install headlightp. 457
+Turn signal lightp. 457
Remove front turn signal lightp. 457
●Remove rear turn signal lightp. 458
Replacement of Turn Signal Light Bulbp. 458
Install turn signal lightp. 458
Remove flasherp. 458
Check flasherp. 459
Install flasherp. 459
+Taillightp. 459
Remove taillightp. 459
Replacement of taillight bulbp. 460
Install taillightp. 460
+License plate lightp. 460
Remove license plate lightp. 460
Replacement of license plate light bulbp. 460
Install license plate lightp. 460
+Gaugep. 461
Remove meterp. 461
Install meterp. 461
+Switch and Sensor and Other Partsp. 462
+Power lock switchp. 463
Remove power lockp. 463
Check power lockp. 463
Install the power lockp. 463
+Handlebar Switchp. 463
Switch state (non-headlights are always on)p. 464
Switch state (headlights are always on)p. 465
Inspection of time for turning on brake lightp. 465
Adjust the time for turning on the brake lightp. 466
+Check switchp. 466
Connect the rear brake light switchp. 466
Connect the sidestand switchp. 466
+Speed sensorp. 466
Remove speed sensorp. 467
Check the speed sensorp. 467
Install speed sensorp. 468
+Oxygen sensorp. 469
Remove oxygen sensorp. 469
Check oxygen sensorp. 469
Install oxygen sensorp. 469
+Fuel level sensorp. 469
Remove fuel level sensorp. 470
Check fuel level sensorp. 470
Installation of fuel level sensorp. 470
+Hornp. 471
Disassemble hornp. 471
Check the hornp. 471
Install hornp. 471
+Fanp. 471
Remove the fanp. 472
Check the fanp. 472
Install the fanp. 473
+Water temperature switchp. 473
Remove the water temperature switchp. 474
Check the water temperature switchp. 474
Install the water temperature switchp. 474
+Relay and fuse boxp. 474
Remove relay and fuse boxp. 475
Inspection of relay circuit:p. 476
Check relay circuit (disconnect battery)p. 476
Check relay circuit (with battery)p. 476
Internal circuit of relay boxp. 477
+Fusep. 478
Remove the fusep. 479
Installation of fusep. 480
Check the fusep. 481
+Chapter VIII Appendixesp. 482
+●Winding method of cables, wires and hosesp. 483
Alignment of main cable:p. 484
Alignment of clutch:p. 491
Alignment of brake pipe:p. 493
Other matters:p. 497
+Troubleshooting Guidep. 499
+Diagnostic procedure for the fault that engine canp. 500
Starter motor does not work:p. 500
The starter motor is rotating, but the engine doesp. 500
The engine does not run:p. 500
Fuel does not flow:p. 500
No sparks; sparks are weak:p. 500
There is a problem with the fuel/air mixture:p. 501
Too low cylinder pressure:p. 501
+It cannot run properly at a low speed:p. 501
Sparks are weak:p. 501
There is a problem with the fuel/air mixture:p. 501
The cylinder pressure is low:p. 501
Others:p. 502
+It cannot run properly at a high speed or the powep. 502
Ignition is abnormal:p. 502
There is a problem with the fuel/air mixture:p. 502
The cylinder pressure is low:p. 502
There is a click sound:p. 502
Others:p. 502
+The temperature is too high:p. 503
Ignition is abnormal:p. 503
The muffler is overheated:p. 503
There is a problem with the fuel/air mixture:p. 503
The cylinder pressure is high:p. 503
The output force of engine is insufficient:p. 503
Not properly lubricated:p. 503
The fuel cooler is abnormal:p. 503
Meter is abnormal:p. 503
The coolant is abnormal:p. 503
The components of cooling system are not working pp. 503
+Overcooling:p. 504
Meter is abnormal:p. 504
The components of cooling system are not working pp. 504
+The clutch is not working properly:p. 504
The clutch is slipping:p. 504
The clutch cannot be separated properly:p. 504
+There is a problem with shifting:p. 504
It is unable to operate the gear smoothly; controlp. 504
Jumpp. 504
Excessive speed change:p. 505
+The engine makes an unusual noise:p. 505
There is a click sound:p. 505
The piston makes a sound:p. 505
The valve makes noise:p. 505
+The drive system makes an unusual noise:p. 505
Clutch makes a noise:p. 505
The drive device makes a noise:p. 506
The drive system makes a noise:p. 506
+The frame makes an unusual noise:p. 506
The front fork makes a noise:p. 506
The rear shock absorber makes a noise:p. 506
The brake disc makes a noise:p. 506
Other noises:p. 506
+Excessive exhaust gas:p. 506
White exhaust:p. 506
Black exhaust:p. 506
Brown exhaust:p. 506
+Poor performance and / or stability:p. 506
It is difficult to rotate the handlebar:p. 506
The handlebars vibrate or shake severely:p. 506
The handlebar is placed on one side:p. 507
The damping effect is not ideal:p. 507
Brake is unable to work properlyp. 507
+Battery has failedp. 507
Battery has run out:p. 507
Battery is overcharged:p. 507
Circuit Diagramp. 508
- Chapter V — Engine
- Lubrication system — exploded view, oil flow diagram, technical parameters, fuel pump (oil pump) disassembly, inspection, installation
- Cylinder head sub-assembly — exploded views, camshaft and valve, timing drive mechanism
- Cylinder head — disassembly, valve decomposition, combustion chamber inspection, joint surface inspection, valve spring inspection, valve stem inspection, valve guide inspection and replacement, valve seat ring adjustment, installation
- Tensioner — function, disassembly, assembly, inspection
- Cylinder block and piston — exploded views, disassembly, installation, inspection
- Crankshaft connecting rod — exploded view, disassembly, assembly, inspection
- Balance shaft — function, disassembly, assembly, inspection
- Clutch — exploded view, special tools, disassembly, installation, inspection
- Gearshift mechanism — exploded view, disassembly, installation, inspection
- Primary/auxiliary shaft component — disassembly, inspection
- Chapter VI — Finished Motorcycle
- Wheel/tire — exploded views, technical parameters, special tools, front/rear wheel removal and installation, wheel and axle inspection, tire pressure, tire inspection, tire removal and installation, hub bearing
- Drive mechanism — exploded view, technical parameters, drive chain inspection and adjustment, sprocket and collar bearing
- Brake — exploded view, technical parameters, brake lever and pedal, caliper, brake pad, master cylinder, brake disc, brake fluid, brake hose, ABS (part position, circuit diagram, pin name, overhaul, diagnostic flow chart, hydraulic mechanism, speed sensor)
- Suspension system — front suspension exploded view, rear suspension exploded view, technical parameters, front shock absorber, rear shock absorber, rear swing arm
- Control system — exploded view, special tools, inspection, adjustment, handlebar, steering stem
- Frame — exploded views (frame, footpegs, muffler, rack, fender, headlight cover, cowling, fuel tank cover, seat cushions, engine accessories), seat cushion, covers, rear rack and side case bracket, side cover, rear fender, front fender, windshield and cowling, headlight cover and panels, fuel tank cover, frame disassembly and inspection, sidestand
- Disassembly/installation of engine — exploded view, removal, installation
- Chapter VII — Electrical System
- Precautions
- Technical parameters
- Special tools
- Electrical wiring and wiring check
- Charging system — circuit diagram, battery (disassembly, installation, activation, first charge, charging state inspection), alternator (disassembly, inspection, installation), voltage regulator/rectifier
- Ignition system — circuit diagram, precautions, crankshaft sensor, ignition coil, spark plug, IC igniter, ECU unit, troubleshooting
- Starter system — circuit diagram, starter motor (disassembly, inspection of brush/commutator/brush lead/end cover, installation), starter relay
- Lighting system — headlight (relay controller, bulb replacement, installation), turn signal light, flasher, taillight, license plate light
- Meters — disassembly, installation
- Switch and sensor — power lock, handlebar switch, brake light switch, speed sensor, oxygen sensor, fuel level sensor, horn, fan, water temperature switch, relay and fuse box, fuse
- Chapter VIII — Appendixes
- Winding method of cables, wires and hoses — main cable alignment, clutch alignment, brake pipe alignment, other matters
- Troubleshooting guide — engine start faults, low-speed running, high-speed running, overheating, clutch, shifting, unusual noises, exhaust, stability, brake, battery
- Circuit diagram
This Benelli TRK 251 service manual is a comprehensive technical document that goes far beyond a simple owner’s handbook. It provides the complete factory-level procedures for maintaining, repairing, and diagnosing the BJ250-18 motorcycle across all major systems. The engine chapter alone covers the lubrication system, cylinder head, cylinder block and piston, crankshaft connecting rod, balance shaft, clutch, and gearshift mechanism with exploded views, disassembly sequences, inspection criteria, and installation torque values. The EFI chapter dives into the Delphi MT05 engine controller, fuel pump, throttle body, fuel injector, oxygen sensor, and the full diagnostic fault code table with troubleshooting flow charts. The brake chapter includes complete ABS coverage with hydraulic mechanism diagnostics and speed sensor testing.
What sets this manual apart is the level of measurement detail. Valve clearance specifications, cylinder bore limits, piston ring end gaps, connecting rod clearances, brake disc thickness limits, drive chain wear limits, fork oil levels, and electrical resistance values are all provided with standard and allowable limit columns. The wiring diagrams and cable routing sections are especially valuable for anyone chasing electrical faults or reassembling a motorcycle after major work. The regular maintenance chapter provides a structured schedule with torque specifications for every major fastener.
What This Manual Enables You to Do
With this Benelli TRK 251 repair guide on hand, you can confidently tackle everything from a routine oil change and valve clearance check to a complete engine teardown and rebuild. The manual walks you through removing and installing the fuel tank, servicing the air filter, replacing the coolant, bleeding the brakes, adjusting the drive chain, setting the steering stem bearing preload, and testing the charging system. For electrical work, the manual provides step-by-step diagnostics for the ignition system, starter circuit, lighting system, and all sensors, including the speed sensor, oxygen sensor, and fuel level sensor.
Having the correct procedures and specifications matters because the TRK 251 combines a relatively high-compression single-cylinder engine with a modern electronic fuel injection system and optional ABS. Torque values that are too low can cause fasteners to loosen under vibration; too high and you risk stripping threads or warping components. Valve clearances outside the specified range will affect engine performance and can lead to burnt valves. The EFI system is sensitive to air leaks and incorrect sensor readings, and the manual’s diagnostic flow charts help isolate the exact cause rather than replacing parts blindly. The ABS system requires careful bleeding procedures and correct tire pressure to function properly, both of which are covered in detail.
This manual is delivered as an instant PDF download. There is no shipping, no waiting for a physical book, and no restrictions on how many times you print or view it. You can access it on any device — laptop, tablet, or smartphone — and print only the pages you need for the job at hand. Whether you are a professional mechanic or a dedicated owner who prefers to maintain their own motorcycle, this Benelli TRK 251 workshop manual gives you the information to do the job right.
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