Description
This 82 page, 1978 Yamaha DT125E DT175E Motorcycle Service & Repair Manual is a reproduction of the original, out of print manual. It is not an original as they are long out of print. This manual has been written to acquaint the mechanic with common disassembly, inspection, reassembly, maintenance, and trouble shooting procedures associated with 1978 Yamaha DT125E DT175E dual sport motorcycles.
Table of Contents
GENERAL INFORMATION
MACHINE IDENTIFICATION
SPECIAL TOOLS AND GAUGES
A Special tools
B Gauges
C Additional tools
PERIODIC INSPECTION AND ADJUSTMENT MAINTENANCE AND LUBRICATION INTERVAL CHARTS
A Periodic Maintenance Chart
B Lubrication Interval Chart
ENGINE
A Carburetor
B Air cleaner
C Autolube pump
D Engine and transmission oil
E Clutch
CHASSIS
A Fuel petcock
B Brakes and wheels
C Drive chain
D Front fork oil change
E Steering
ELECTRICAL
A Contact breaker point for DT125E
B Ignition timing for DT125E (Flywheel)
C Ignition timing for DT175E (CDI)
D Spark plug
E Battery
F Headlight
ENGINE OVERHAUL
ENGINE REMOVAL
A Preparation for removal
B Fuel tank assembly
C Muffler
D Wiring and cables
E Carburetor
F Flywheel magneto
G Change pedal
H Drive chain
I Removal
ENGINE DISASSEMBLY
A Reed valve assembly
B Cylinder head and cylinder
C Piston pin and piston
D Kick crank
E Crankcase cover, right
F Clutch assembly and primary drive gear
G Kick axle assembly and kick idle gear
H Change shaft assembly
I Clutch push lever axle
J Neutral switch
K Crankcase
L Transmission
M Crankshaft
ENGINE INSPECTION AND REPAIR
A Cylinder head
B Cylinder
C Piston
D Piston rings
E Piston pin and bearing
F Autolube pump
G Clutch
H Primary drive
I Kick starter mechanism
J Transmission
K Crankshaft
L Bearings and oil seals
M Crankcase
ENGINE ASSEMBLY AND ADJUSTMENT
A Crankshaft installation
B Transmission and shifter installation
C Crankcase
D Change shaft assembly and neutral switch
E Kick starter assembly
F Kick idle, tachometer drive and primary drive gears
G Clutch and clutch push lever axle
H Crankcase cover, right
I Piston
J Cylinder head and cylinder
ENGINE MOUNTING
CARBURETION
CARBURETOR
A Inspection
B Adjustment
REED VALVE ASSEMBLY
A Inspection
CHASSIS
MONOCROSS SUSPENSION (DE CARBON SYSTEM)
A Construction
B Principles of operation
C Handling notes
D Adjustment
E Removal
F Spring replacement
WHEELS
A Axles
B Checking brake shoe wear
C Brake drum
D Replacing wheel bearings
RIMS AND SPOKES
A Checking for loose spokes
B Checking rim “Run-out”
DRIVE CHAIN AND SPROCKET
A Chain inspection
B Drive sprocket & Driven sprocket
FRONT FORKS
A Disassembly
B Inspection
C Reassembly
STEERING HEAD
A Inspection
SWING ARM
A Inspection
B Lubrication
CABLES AND FITTINGS
A Cable maintenance
B Throttle maintenance
ELECTRICAL
IGNITION SYSTEM FOR DT125E
A Spark gap test
B Ignition coil test
C Condenser test
IGNITION SYSTEM FOR DT175E
A Capacitor discharge ignition
B Checking the magneto pulser coil
CHARGING SYSTEM
A Charging output test
B Checking silicon rectifier
LIGHTING AND SIGNAL SYSTEMS
A Voltage regulator (AC regulator)
B Lighting tests and checks — AC circuit
C Lighting tests and checks — DC circuit
APPENDICES
GENERAL SPECIFICATIONS
A General
B Engine
C Chassis
D Electrical
TORQUE SPECIFICATIONS
CABLE ROUTING DIAGRAMS
CIRCUIT DIAGRAM
