14 V 3 W V 3 W V 3 W 1 Constant mesh 3D9/SHY 0.4 kW 0.017 ~ 0.021 10.0 mm (0.39 in) 5.52 ~ 8.28 N (563 ~ 844 gf, 19.87 ~ 29.80 oz) 22.0 mm (0.87 in) 1.5 mm (0.06 in) SANXIN 150 A 3.6 ~ 4.4 Plane YF-12/NIKKO 1 3.0 A 1.15 ~ 1.~ 120 dB/2 m Condenser No 75 ~ 95 cycles/min. 10 W 2 + 1.7 W LOCAL MADE 4 ~ 10 at 20 C (68 F) 90 ~ 100 at 20 C (68 F) 15 A 15 A
---------------------3.5 mm (0.14 in) ---21.0 mm (0.83 in) -------------------------------------------------------

2 - 15

CONVERSION TABLE/ GENERAL TIGHTENING TORQUE SPECIFICATIONS

EAS00028 EAS00030

CONVERSION TABLE
All specification data in this manual are listed in SI and METRIC UNITS. Use this table to convert METRIC unit data to IMPERIAL unit data. Ex. METRIC ** mm 2 mm MULTIPLIER 0.03937 0.03937 = = IMPERIAL ** in 0.08 in
GENERAL TIGHTENING TORQUE SPECIFICATIONS
This chart specifies tightening torques for standard fasteners with a standard ISO thread pitch. Tightening torque specifications for special components or assemblies are provided for each chapter of this manual. To avoid warpage, tighten multi-fastener assemblies in a crisscross pattern and progressive stages until the specified tightening torque is reached. Unless otherwise specified, tightening torque specifications require clean, dry threads. Components should be at room temperature.
METRIC TO IMPERIAL Metric unit mkg Tightening torque mkg cmkg cmkg Weight Speed kg g km/hr km m m cm mm cc (cm3) cc (cm3) lt (liter) lt (liter) kg/mm kg/cm2 Centigrade (C) Multiplier 7.233 86.794 0.0723 0.8679 2.205 0.03527 0.6214 0.6214 3.281 1.094 0.3937 0.03937 0.03527 0.06102 0.8799 0.2199 55.997 14.2234 9/5+32 Imperial unit ftlb inlb ftlb inlb lb oz mph mi ft yd in in oz (IMP lip.) cu.in qt (IMP liq.) gal (IMP liq.) lb/in psi (lb/in2) Fahrenheit (F)

Distance

A: Distance between flats B: Outside thread diameter A (nut) 10 mm 12 mm 14 mm 17 mm 19 mm 22 mm B (bolt) 6 mm 8 mm 10 mm 12 mm 14 mm 16 mm General tightening torques Nm m kg 0.6 1.5 3.0 5.5 8.5 13.0 ft lb 4.61 94

Volume/ Capacity

2 - 16
TIGHTENING TORQUES TIGHTENING TORQUES
ENGINE TIGHTENING TORQUES Part to be tightened Cylinder head Oil gallery bolt Spark plug Camshaft sprocket cover Tappet cover (intake and exhaust side) A.C. magneto rotor Timing chain guide (intake side) Valve adjusting screw locknut (intake and exhaust side) Camshaft sprocket Camshaft retainer Timing chain tensioner cap Timing chain tensioner Oil pump assembly Oil pump housing cover Engine oil drain bolt Intake manifold (cylinder head side) Intake manifold (carburetor side) Carburetor joint clamp Air filter case Exhaust pipe and cylinder head Muffler and passenger footrest bracket Exhaust pipe protector Muffler protector Air cut-off valve assembly Air induction system pipe and cylinder head Crankcase A.C. magneto rotor cover Clutch cover Stator coil lead holder Timing mark accessing screw Crankshaft end accessing screw Kickstarter lever Starter clutch idle gear holder Starter motor Starter clutch Primary drive gear Part name Bolt Bolt Bolt Bolt Nut Bolt Nut Bolt Bolt Bolt Bolt Screw Screw Bolt Bolt Bolt Screw Bolt Bolt Bolt Screw Screw Screw Bolt Bolt Bolt Bolt Screw Nut Screw Bolt Bolt Nut Thread Qty size M8 M6 M6 M10 M6 M45 M12 M6 M5 M8 M6 M6 M6 M6 M5 M12 M6 M6 M4 M6 M6 M8 M6 M6 M6 M6 M6 M6 M6 M6 M14 M32 M12 M6 M6 M8 M3 1

3 - 13

CHECKING THE SPARK PLUG

EAS00060

CHECKING THE SPARK PLUG 1. Disconnect: spark plug cap 2. Remove: spark plug CAUTION:
Before removing the spark plug, blow away any dirt accumulated in the spark plug well with compressed air to prevent it from falling into the cylinder. 3. Check: spark plug type Incorrect Change. Spark plug type (manufacturer) CR6HSA (NGK)
4. Check: electrode 1 Damage/wear Replace the spark plug. insulator 2 Abnormal color Replace the spark plug. Normal color is medium-to-light tan. 5. Clean: spark plug (with a spark plug cleaner or wire brush) 6. Measure: spark plug gap a (with a wire thickness gauge) Out of specification Regap. Spark plug gap 0.6 ~ 0.7 mm (0.024 ~ 0.028 in) 7. Install: spark plug
13 Nm (1.3 m kg, 9.4 ft lb)
NOTE: Before installing the spark plug, clean the spark plug and gasket surface. 8. Connect: spark plug cap

3 - 14

CHECKING THE IGNITION TIMING

EAS00064

CHECKING THE IGNITION TIMING NOTE: Prior to checking the ignition timing, check the wiring connections of the entire ignition system. Make sure all connections are tight and free of corrosion.
Remove: timing mark accessing screw Connect: timing light 1 (onto the spark plug lead) Timing light 90890-03141, YU-03141
3. Check: ignition timing
a. Start the engine, warm it up for several minutes, and then let it run at the specified engine idling speed. Engine idling speed 1,400 ~ 1,500 r/min b. Check that the stationary pointer a is within the firing range b on the A.C. magneto rotor. Incorrect firing range Check the ignition system. NOTE: The ignition timing is not adjustable.

4. 5.

Disconnect: timing light Install: timing mark accessing screw

3 - 15

MEASURING THE COMPRESSION PRESSURE

EAS00067

MEASURING THE COMPRESSION PRESSURE NOTE: Insufficient compression pressure will result in a loss of performance.
1. Measure: valve clearance Out of specification Adjust. Refer to ADJUSTING THE VALVE CLEARANCE. 2. Start the engine, warm it up for several minutes, and then turn it off. 3. Disconnect: spark plug cap 4. Remove: spark plug CAUTION:

* Total weight of rider, passenger, cargo and accessories
It is dangerous to ride with a worn-out tire. When the tire tread reaches the wear limit, replace the tire immediately.

3 - 37

2. Check: tire surfaces Damage/wear Replace the tire. Minimum tire tread depth 1.6 mm (0.06 in)
1 Tire tread depth 2 Sidewall 3 Wear indicator
Do not use a tubeless tire on a wheel designed only for tube tires to avoid tire failure and personal injury from sudden deflation. When using tube tires, be sure to install the correct tube. Always replace a new tube tire and a new tube as a set. To avoid pinching the tube, make sure the wheel rim band and tube are centered in the wheel groove. Patching a punctured tube is not recommended. If it is absolutely necessary to do so, use great care and replace the tube as soon as possible with a good quality replacement.

Tire Wheel

Tube wheel Tubeless wheel
Tube tire only Tube or tubeless tire
After extensive tests, the tires listed below have been approved by Yamaha Motor Co., Ltd. for this model. The front and rear tires should always be by the same manufacturer and of the same design. No guarantee concerning handling characteristics can be given if a tire combination other than one approved by Yamaha is used on this vehicle.

3 - 38

Front tire Manufacturer CHENG SHIN PIRELLI Rear tire Manufacturer CHENG SHIN PIRELLI WARNING
Size 2.75-18 42P 2.75-18 42P
Model SAKURA S-901 CITY DEMON
Model SAKURA S-180 CITY DEMON
Size 90/9018 57P 90/9018 57P
New tires have a relatively low grip on the road surface until they have been slightly worn. Therefore, approximately 100 km should be traveled at normal speed before any high-speed riding is done. After a tire has been repaired or replaced, be sure to tighten the tire air valve stem locknut 1 to specification. NOTE: For tires with a direction of rotation mark 2: Install the tire with the mark pointing in the direction of wheel rotation. Align the mark 3 with the valve installation point.

Tire air valve stem locknut 2 Nm (0.2 m kg, 1.4 ft lb)

3 - 39

CHECKING THE WHEELS/ CHECKING AND LUBRICATING THE CABLES

EAS00168

CHECKING THE WHEELS The following procedure applies to both of the wheels. 1. Check: wheel Damage/out-of-round Replace. WARNING
Never attempt to make any repairs to the wheel. NOTE: After a tire or wheel has been changed or replaced, always balance the wheel.

EAS00170

CHECKING AND LUBRICATING THE CABLES The following procedure applies to all of the inner and outer cables. WARNING
Damaged outer cable may cause the cable to corrode and interfere with its movement. Replace damaged outer cable and inner cables as soon as possible. 1. Check: outer cable Damage Replace. 2. Check: cable operation Rough movement Lubricate. Recommended lubricant Engine oil or a suitable cable lubricant NOTE: Hold the cable end upright and pour a few drops of lubricant into the cable sheath or use a suitable lubricating device.

3 - 40

LUBRICATING THE LEVERS AND PEDALS/ LUBRICATING THE CENTERSTAND

EAS00171

LUBRICATING THE LEVERS AND PEDALS Lubricate the pivoting point and metal-to-metal moving parts of the levers and pedals. Recommended lubricant Lithium-soap-based grease

EAS00173

LUBRICATING THE CENTERSTAND Lubricate the pivoting point and metal-to-metal moving parts of the centerstand. Recommended lubricant Lithium-soap-based grease

3 - 41

CHECKING AND CHARGING THE BATTERY

EAS00176

ELECTRICAL SYSTEM

E NG D DAACI

CHECKING AND CHARGING THE BATTERY WARNING
Batteries generate explosive hydrogen gas and contain electrolyte which is made of poisonous and highly caustic sulfuric acid. Therefore, always follow these preventive measures: Wear protective eye gear when handling or working near batteries. Charge batteries in a well-ventilated area. Keep batteries away from fire, sparks or open flames (e.g., welding equipment, lighted cigarettes). DO NOT SMOKE when charging or handling batteries. KEEP BATTERIES AND ELECTROLYTE OUT OF REACH OF CHILDREN. Avoid bodily contact with electrolyte as it can cause severe burns or permanent eye injury. FIRST AID IN CASE OF BODILY CONTACT: EXTERNAL Skin Wash with water. Eyes Flush with water for 15 minutes and get immediate medical attention. INTERNAL Drink large quantities of water or milk followed with milk of magnesia, beaten egg or vegetable oil. Get immediate medical attention. 1. Remove: left side cover Refer to SIDE COVERS, SEAT AND FUEL TANK.

3. Fill: brake master cylinder reservoir (with the specified amount of the recommended brake fluid) Recommended brake fluid DOT 3 or 4 WARNING
Use only the designated brake fluid. Other brake fluids may cause the rubber seals to deteriorate, causing leakage and poor brake performance. Refill with the same type of brake fluid that is already in the system. Mixing brake fluids may result in a harmful chemical reaction, leading to poor brake performance. When refilling, be careful that water does not enter the brake master cylinder reservoir. Water will significantly lower the boiling point of the brake fluid and could cause vapor lock. CAUTION:
Brake fluid may damage painted surfaces and plastic parts. Therefore, always clean up any spilt brake fluid immediately.

4 - 27

4. Bleed: brake system Refer to BLEEDING THE HYDRAULIC BRAKE SYSTEM in chapter 3. 5. Check: brake fluid level Below the minimum level mark a Add the recommended brake fluid to the proper level. Refer to CHECKING THE BRAKE FLUID LEVEL in chapter 3. 6. Check: brake lever operation Soft or spongy feeling Bleed the brake system. Refer to BLEEDING THE HYDRAULIC BRAKE SYSTEM in chapter 3.

4 - 28

EAS00612

FRONT BRAKE CALIPER

35 Nm (3.5 m kg, 25 ft Ib)
25 Nm (2.5 m kg, 18 ft Ib)
Job/Part Removing the front brake caliper Brake fluid Union bolt Copper washer Brake hose Brake caliper bolt
Brake caliper bracket bolt Brake caliper
Remarks Remove the parts in the order listed. Drain. Refer to DISASSEMBLING THE FRONT BRAKE CALIPER and ASSEMBLING AND Loosen. INSTALLING THE FRONT BRAKE CALIPER. Refer to ASSEMBLING AND INSTALLING THE FRONT BRAKE CALIPER. For installation, reverse the removal procedure.

4 - 29

EAS00614
Job/Part Disassembling the front brake caliper Brake caliper bolt Brake caliper bracket Bleed screw Brake pad Brake pad shim Brake pad spring Brake caliper piston Dust boot Brake caliper piston seal Brake caliper body
Refer to DISASSEMBLING THE FRONT BRAKE CALIPER.

4 - 30

EAS00618
DISASSEMBLING THE FRONT BRAKE CALIPER NOTE: Before disassembling the brake caliper, drain the brake fluid from the entire brake system.

1. 2.

Loosen: brake caliper bolt 1 Remove: union bolt 2 copper washers 3 brake hose 4
NOTE: Put the end of the brake hose into a container and pump out the brake fluid carefully.
Remove: brake caliper piston 1 dust boot 2 brake caliper piston seal 3
a. Blow compressed air into the brake hose joint opening a to force out the piston from the brake caliper. WARNING

Cover the brake caliper piston with a rag. Be careful not to get injured when the piston is expelled from the brake caliper. Never try to pry out the brake caliper piston. b. Remove the dust boot and brake caliper piston seal.

4 - 31

EAS00630
CHECKING THE FRONT BRAKE CALIPER Recommended brake component replacement schedule Brake pads Piston seals Brake hose If necessary Every two years Every four years Every two years and whenever the brake is disassembled

Brake fluid

1. Check: brake caliper piston 1 Rust/scratches/wear Replace the brake caliper piston. brake caliper cylinder 2 Scratches/wear Replace the brake caliper assembly. brake caliper body 3 Cracks/damage Replace the brake caliper assembly. brake fluid delivery passage (brake caliper body) Obstruction Blow out with compressed air. WARNING
Whenever a brake caliper is disassembled, replace the piston seals. 2. Check: brake caliper bracket Cracks/damage Replace.

4 - 32

EAS00634
ASSEMBLING AND INSTALLING THE FRONT BRAKE CALIPER WARNING
Before installation, all internal brake components should be cleaned and lubricated with clean or new brake fluid. Never use solvents on internal brake components as they will cause the piston seals to swell and distort. Whenever a brake caliper is disassembled, replace the brake caliper piston seals. Recommended brake fluid DOT 3 or 4 1. Install: brake caliper bracket
35 Nm (3.5 m kg, 25 ft lb)

3 New 1

2. Install: brake caliper (temporarily) copper washers 1 New brake hose 2 union bolt Nm (2.5 m kg, 18 ft lb)
Proper brake hose routing is essential to insure safe vehicle operation. Refer to CABLE ROUTING in chapter 2. CAUTION:
When installing the brake hose onto the brake caliper, make sure the brake pipe touches the projection a on the brake caliper. 3. Remove: brake caliper

4 - 33

Install: brake pad springs brake pad shim brake pads 23 Nm (2.3 m kg, 17 ft lb) brake caliper Refer to REPLACING THE FRONT BRAKE PADS. 5. Fill: brake master cylinder reservoir (with the specified amount of the recommended brake fluid) Recommended brake fluid DOT 3 or 4 WARNING

4 - 61

2. Check: drive chain Stiffness Clean and lubricate or replace. 3. Clean: drive chain
a. Wipe the drive chain with a clean cloth. b. Put the drive chain in kerosene and remove any remaining dirt. c. Remove the drive chain from the kerosene and completely dry it. CAUTION:
This vehicle has a drive chain with small rubber O-rings 1 between the drive chain side plates. Never use high-pressure water or air, steam, gasoline, certain solvents (e.g., benzine), or a coarse brush to clean the drive chain. High-pressure methods could force dirt or water into the drive chains internals, and solvents will deteriorate the O-rings. A coarse brush can also damage the O-rings. Therefore, use only kerosene to clean the drive chain. Dont soak the drive chain in kerosene for more than ten minutes, otherwise the O-rings can be damaged.
4. Check: O-rings 1 Damage Replace the drive chain. drive chain rollers 2 Damage/wear Replace the drive chain. drive chain side plates 3 Damage/wear Replace the drive chain. Cracks Replace the drive chain and make sure the battery breather hose is properly routed away from the drive chain and below the swingarm. 5. Lubricate: drive chain Recommended lubricant Engine oil or chain lubricant suitable for O-ring chains

4 - 62

6. Check: drive sprocket rear wheel sprocket More than 1/4 tooth a wear Replace the drive chain, drive sprocket and rear wheel sprocket as a set. Bent teeth Replace the drive chain, drive sprocket and rear wheel sprocket as a set.
b Correct 1 Drive chain roller 2 Drive chain sprocket

EAS00713

INSTALLING THE DRIVE CHAIN 1. Lubricate: drive chain master link New Recommended lubricant Engine oil or chain lubricant suitable for O-ring chains 2. 3.
Install: drive sprocket drive sprocket holder drive sprocket bolts (temporarily) Install: master link body O-rings master link plate master link clip 1 New
CAUTION: The closed end of the master link clip must face in the direction of drive chain rotation. Never install a new drive chain onto worn drive chain sprockets; this will dramatically shorten the drive chains life. 4. Install: rear wheel Refer to REAR WHEEL, BRAKE SHOE PLATE, AND REAR WHEEL SPROCKET.

4 - 63

5. Tighten: drive sprocket bolts
NOTE: Tighten the drive sprocket bolts while pressing the brake pedal. 6. Install: drive sprocket cover
NOTE: Proper neutral switch lead routing is essential to insure safe vehicle operation. Refer to CABLE ROUTING in chapter 2. 7. Adjust: drive chain slack Refer to ADJUSTING THE DRIVE CHAIN SLACK in chapter 3. Drive chain slack 20 ~ 30 mm (0.79 ~ 1.18 in) CAUTION:

5 - 44

8. Install: friction plates clutch plates
NOTE: First, install a friction plate and then alternate between a clutch plate and a friction plate.
Install: pressure plate 1 clutch springs 2 clutch spring bolts 3
6 Nm (0.6 m kg, 4.3 ft lb)
NOTE: Tighten the clutch spring bolts in stages and in a crisscross pattern.

1 c a b

10.Adjust: clutch mechanism free play a. Check that projection a on the clutch push lever 1 aligns with mark b on the crankcase by pushing the clutch push lever manually in direction c until it stops. b. If projection a is not aligned with mark b, align them as follows: Loosen the locknut 2. With the clutch push lever fully pushed in direction c, turn the short clutch push rod 3 in or out until projection a aligns with mark b. Hold the short clutch push rod to prevent it from moving and then tighten the locknut to specification. Locknut 8 Nm (0.8 m kg, 5.8 ft lb)

11.Install: clutch cover

3,12 2,9
NOTE: Tighten the clutch cover bolts in the proper tightening sequence as shown.

5 - 45

12.Install: kickstarter lever 1
50 Nm (5.0 m kg, 36 ft lb)
NOTE: Install the kickstarter lever as close as possible to the clutch cover, making sure that the lever does not contact the area a of the clutch cover. 13.Adjust: clutch cable free play Refer to ADJUSTING THE CLUTCH CABLE FREE PLAY in chapter 3.

5 - 46

SHIFT SHAFT AND STOPPER LEVER

EAS00327

New 3 4
12 Nm (1.2 m kg, 8.7 ft Ib)
Job/Part Removing the shift shaft and stopper lever Clutch housing Shift pedal Shift shaft Circlip Shift shaft spring Stopper lever Stopper lever spring Shift drum segment Dowel pin
Remarks Remove the parts in the order listed. Refer to CLUTCH.
Refer to INSTALLING THE SHIFT SHAFT AND SHIFT PEDAL.

5 - 47

EAS00328
CHECKING THE SHIFT SHAFT 1. Check: shift shaft shift lever Bends/damage/wear Replace. shift lever spring Damage/wear Replace.

EAS00330

CHECKING THE STOPPER LEVER 1. Check: stopper lever Bends/damage Replace. Roller turns roughly Replace the stopper lever. stopper lever spring Damage/wear Replace. CHECKING THE SHIFT DRUM SEGMENT 1. Check: shift drum segment Damage/wear Replace the shift drum segment.

EAS00331

INSTALLING THE SHIFT SHAFT AND SHIFT PEDAL 1. Install: stopper lever 1 stopper lever spring 2 stopper lever bolt
NOTE: Hook the ends of the stopper lever spring onto the stopper lever and the crankcase boss 3. Install the stopper lever spring as shown in the illustration. Mesh the stopper lever with the shift drum segment.

a. Wash the carburetor in a petroleum-based solvent. Do not use any caustic carburetor cleaning solution. b. Blow out all of the passages and jets with compressed air.
3. Check: float chamber body Dirt Clean. 4. Check: float chamber rubber gasket Cracks/damage/wear Replace. 5. Check: float Damage Replace.
6. Check: needle valve 1 needle valve seat 2 Damage/obstruction/wear Replace the needle valve, needle valve seat and O-ring as a set. 7. Check: O-ring 3 Damage/wear Replace the needle valve, needle valve seat and O-ring as a set. 8. Check: throttle valve Damage/scratches/wear Replace. 9. Check: throttle valve spring Cracks/damage Replace.
10.Check: coasting enricher diaphragm spring coasting enricher diaphragm cover Tears/damage Replace.
11.Check: jet needle kit 1 pilot screw 2 pilot jet 3 main jet 4 needle jet holder 5 needle jet 6 throttle stop screw 7 Bends/damage/wear Replace. Obstruction Clean. Blow out the jets with compressed air. 12.Check: throttle valve movement Insert the throttle valve into the carburetor body and move it up and down. Tightness Replace the throttle valve. 13.Check: starter plunger starter plunger spring Bends/cracks/damage Replace. 14.Check: hose joints Cracks/damage Replace. 15.Check: air vent hoses fuel hose Cracks/damage/wear Replace. Obstruction Clean. Blow out the hoses with compressed air.

EAS00487

ASSEMBLING THE CARBURETOR CAUTION:
Before assembling the carburetor, wash all of the parts in a petroleum-based solvent. Always use a new gasket.
1. Install: pilot screw 1
Pilot screw setting 1-1/2 turns out
2. Install: needle valve seat 1 needle valve seat holder 2 NOTE: Install the needle valve seat holder with its bent ends a facing downwards as shown.
3. Measure: float height a Out of specification Adjust.
Float height (F.H.) 21.8 mm (0.86 in)
a. Hold the carburetor in an upside down position. b. Measure the distance from the front mating surface of the float chamber (gasket removed) to the top of the float. NOTE: The float arm should be resting on the needle valve, but not compressing it. c. If the float height is not within the specification, check the valve seat and needle valve. d. If either is worn, replace them both. e. If both are fine, adjust the float height by bending the float tang 1 on the float. f. Recheck the float height.

EAS00492

INSTALLING THE CARBURETOR 1. Adjust: engine idling speed Engine idling speed 1,400 ~ 1,500 r/min Refer to ADJUSTING THE IDLING SPEED in chapter 3. 2. Adjust: throttle cable free play ENGINE

Be sure to hold the socket firmly when removing the bulb. Never pull the lead, otherwise it may be pulled out of the terminal in the coupler. Avoid touching the glass part of the headlight bulb to keep it free from oil, otherwise the transparency of the glass, the life of the bulb, and the luminous flux will be adversely affected. If the headlight bulb gets soiled, thoroughly clean it with a cloth moistened with alcohol or lacquer thinner. 2. Check: bulb (for continuity) (with the pocket tester) No continuity Replace. Pocket tester 90890-03112, YU-03112-C NOTE: Before checking for continuity, set the pocket tester to 0 and to the 1 range.
a. Connect the positive tester probe to terminal 1 and the negative tester probe to terminal 2, and check the continuity. b. Connect the positive tester probe to terminal 1 and the negative tester probe to terminal 3, and check the continuity. c. If either of the readings indicate no continuity, replace the bulb.
CHECKING THE CONDITION OF THE BULB SOCKETS The following procedure applies to all of the bulb sockets. 1. Check: bulb socket (for continuity) (with the pocket tester) No continuity Replace. Pocket tester 90890-03112, YU-03112-C NOTE: Check each bulb socket for continuity in the same manner as described in the bulb section; however, note the following.
a. Install a good bulb into the bulb socket. b. Connect the pocket tester probes to the respective leads of the bulb socket. c. Check the bulb socket for continuity. If any of the readings indicate no continuity, replace the bulb socket.

EAS00734

R R O L/Y W/B B W Br R

1 A B C

LOCK OFF ON R (BLACK) Br Br L/W (RED) L/W (RED) Br B B/W B B R Br B/W B/W Br R W W/B L/Y Br B O B/W

CIRCUIT DIAGRAM

IGNITION SYSTEM
R R R L/W L/W (RED) Sb L/W L/W Br Br

L/W Br

L/W L/W Sb L/B W/B R/B Br Br Br Br B B (BLACK) B B B Y Br Y P Y Y Y (BLACK) B R/B Br

W/B L/B Br Br

7 F J L

Br Br/W Br Br/W Y B B

L/B Br/W P
Br/W L/B P Dg Ch B (BLUE) Y Y Y G G B Ch Dg (BLUE) B B Ch Dg P L/B Br/W

(BLACK)

Z [ \ ]
Ch Ch Dg Dg Y L G Ch Dg Y B Y B G

B (GREEN) B

1 A.C. magneto 4 Battery 5 Fuse 8 Main switch A C.D.I. unit B Ignition coil C Spark plug

EAS00736 EAS00739

TROUBLESHOOTING The ignition system fails to operate (no spark or intermittent spark). Check: 1. fuse 2. battery 3. spark plug 4. ignition spark gap 5. spark plug cap resistance 6. ignition coil resistance 7. pickup coil resistance 8. main switch 9. wiring connections (of the entire ignition system) NOTE: Before troubleshooting, remove the following part(s): 1. left side cover 2. headlight assembly 3. air duct (left and right) 4. fuel tank Troubleshoot with the following special tool(s).
2. Battery Check the condition of the battery. Refer to CHECKING AND CHARGING THE BATTERY in chapter 3. Minimum open-circuit voltage 12.8 V or more at 20 C (68 F) Is the battery OK? YES NO Refill battery fluid. Clean the battery terminals. Recharge or replace the battery.

7 - 14

EAS00761 EAS00760
4. Starter relay Remove the starter relay. Connect the pocket tester ( 1) and battery (12 V) to the starter relay terminals as shown. Positive battery terminal blue/white 1 Negative battery terminal blue/white 2 Positive tester probe red 3 Negative tester probe black 4
5. Diode Remove the diode from the coupler. Connect the pocket tester ( 1) to the diode terminals as shown. Measure the diode for continuity as follows. NOTE: The pocket tester readings are shown in the following table. Positive tester probe sky blue 1 Continuity Negative tester probe blue/white 2 Positive tester probe blue/white 2 No continuity Negative tester probe sky blue 1
Does the starter relay have continuity between red and black? YES NO Replace the starter relay.

Sb L/W

Are the testing readings correct? YES NO Replace the diode.

7 - 15

EAS00749 EAS00764
6. Main switch Check the main switch for continuity. Refer to CHECKING THE SWITCHES. Is the main switch OK? YES Replace switch.

EAS00751

9. Start switch Check the start switch for continuity. Refer to CHECKING THE SWITCHES. Is the start switch OK? YES NO Replace the right handlebar switch.

EAS00766

NO the main
7. Neutral switch Check the neutral switch for continuity. Refer to CHECKING THE SWITCHES. Is the neutral switch OK? YES NO Replace the neutral switch.

EAS00763

10.Wiring Check the entire starting systems wiring. Refer to CIRCUIT DIAGRAM. Is the starting systems wiring properly connected and without defects? YES The starting system circuit is OK. NO Properly connect or repair the starting systems wiring.
8. Clutch switch Check the clutch switch for continuity. Refer to CHECKING THE SWITCHES. Is the clutch switch OK? YES NO Replace the clutch switch.

7 - 16

STARTER MOTOR

EAS00767

Order 1 2
Job/Part Removing the starter motor Starter motor Starter motor lead

YES The horn is OK.

EAS00797

NO Replace the horn.

2. The tail/brake light fails to come on. 1. Tail/brake light bulb and socket Check the tail/brake light bulb and socket for continuity. Refer to CHECKING THE BULBS AND BULB SOCKETS. Are the tail/brake light bulb and socket OK? YES NO Replace the tail/ brake light bulb, socket or both. 2. Brake light switches Check the brake light switches for continuity. Refer to CHECKING THE SWITCHES. Are the brake light switches OK? YES NO Replace the brake light switch(es).
Set the main switch to ON. Measure the voltage (DC 12 V) of brown at the horn terminal. Is the voltage within specification? YES NO The wiring circuit from the main switch to the horn connector is faulty and must be repaired.

7 - 35

3. Voltage Connect the pocket tester (DC 20 V) to the tail/brake light coupler (wire harness side) as shown. Positive tester probe yellow 1 Negative tester probe black 2

EAS00799

3. The turn signal light, turn signal indicator light or both fail to blink. 1. Turn signal light bulb and socket Check the turn signal light bulb and socket for continuity. Refer to CHECKING THE BULBS AND BULB SOCKETS. Are the turn signal light bulb and socket OK? YES NO Replace the turn signal light bulb, socket or both.
Set the main switch to ON. Pull in the brake lever or push down on the brake pedal. Measure the voltage (DC 12 V) of yellow 1 on the tail/brake light coupler (wire harness side). Is the voltage within specification? YES This circuit is OK. NO The wiring circuit from the main switch to the tail/brake light coupler is faulty and must be repaired.
2. Turn signal indicator light bulb and socket Check the turn signal indicator light bulb and socket for continuity. Refer to CHECKING THE BULBS AND BULB SOCKETS. Are the turn signal indicator light bulb and socket OK? YES NO Replace the turn signal indicator light bulb, socket or both. 3. Turn signal switch Check the turn signal switch for continuity. Refer to CHECKING THE SWITCHES. Is the turn signal switch OK? YES NO The turn signal switch is faulty. Replace the left handlebar switch.

7 - 36

4. Voltage Connect the pocket tester (DC 20 V) to the turn signal relay coupler as shown. Positive tester probe brown 1 Negative tester probe ground 5. Voltage
Connect the pocket tester (DC 20 V) to the turn signal relay coupler as shown. Positive tester probe brown/white 1 Negative tester probe ground

UNSTABLE HANDLING

EAS00862
Handlebar Bent or improperly installed handlebar Steering head components Improperly installed upper bracket Improperly installed lower bracket (improperly tightened ring nut) Bent steering stem Damaged ball bearing or bearing race Front fork leg(s) Uneven oil levels (both front fork legs) Unevenly tensioned fork spring (both front fork legs) Broken fork spring Bent or damaged inner tube Bent or damaged outer tube Swingarm Worn bushing Bent or damaged swingarm Rear shock absorber assembly(ies) Faulty rear shock absorber spring Leaking oil Tire(s) Uneven tire pressures (front and rear) Incorrect tire pressure Uneven tire wear Wheel(s) Incorrect wheel balance Deformed cast wheel Damaged wheel bearing Bent or loose wheel axle Excessive wheel runout Frame Bent frame Damaged steering head pipe Improperly installed bearing race
FAULTY LIGHTING OR SIGNALING SYSTEM

EAS00866

HEADLIGHT DOES NOT COME ON Wrong headlight bulb Too many electrical accessories Hard charging Incorrect connection Improperly grounded circuit Poor contacts (main or light switch) Burnt-out headlight bulb HEADLIGHT BULB BURNT OUT Wrong headlight bulb Faulty battery Faulty rectifier/regulator Improperly grounded circuit Faulty main switch Faulty light switch Headlight bulb life expired TAIL/BRAKE LIGHT DOES NOT COME ON Wrong tail/brake light bulb Too many electrical accessories Incorrect connection Burnt-out tail/brake light bulb TAIL/BRAKE LIGHT BULB BURNT OUT Wrong tail/brake light bulb Faulty battery Incorrectly adjusted rear brake light switch Tail/brake light bulb life expired TURN SIGNAL DOES NOT COME ON Faulty turn signal switch Faulty turn signal relay Burnt-out turn signal bulb Incorrect connection Damaged or faulty wire harness Improperly grounded circuit Faulty battery Blown, damaged or incorrect fuse TURN SIGNALS FLASH SLOWLY Faulty turn signal relay Faulty main switch Faulty turn signal switch Incorrect turn signal bulb TURN SIGNALS REMAIN LIT Faulty turn signal relay Burnt-out turn signal bulb TURN SIGNALS FLASH QUICKLY Incorrect turn signal bulb Faulty turn signal relay Burnt-out turn signal bulb HORN DOES NOT SOUND Improperly adjusted horn Damaged or faulty horn Faulty main switch Faulty horn switch Faulty battery Blown, damaged or incorrect fuse Faulty wire harness
YBR125ED 2005 WIRING DIAGRAM
1 A.C. magneto 2 Neutral switch 3 Rectifier/regulator 4 Battery 5 Fuse 6 Starter relay 7 Starter motor 8 Main switch 9 Right handlebar switch 0 Start switch A C.D.I. unit B Ignition coil C Spark plug D Headlight relay E Diode F Clutch switch G Thermo switch H Carburetor heater I Rear brake light switch J Front brake light switch K Turn signal relay L Horn M Left handlebar switch N Dimmer switch O Horn switch P Turn signal switch Q Headlight assembly R Headlight S Auxiliary light T Front turn signal light (left) U Rear turn signal light (left) V Rear turn signal light (right) W Front turn signal light (right) X Tail/brake light Y Meter assembly Z Fuel gauge [ Tachometer \ Neutral indicator light ] Meter light _ High beam indicator light a Right turn signal indicator light b Left turn signal indicator light c Fuel sender COLOR CODE B. Black Br. Brown Ch.. Chocolate Dg.. Dark green G. Green L. Blue Sb.. Sky blue O. Orange P. Pink R. Red W. White Y. Yellow B/W. Black/White Br/W. Brown/White L/B. Blue/Black L/W. Blue/White L/Y. Blue/Yellow R/B. Red/Black W/B. White/Black

FIG. 38 EQUIPO ELECTRICO 1

ELECTRICAL 1

1 42KH90445081A4VWH5HHH5HHH5HHH9851M9290M12R5HH42X9502M5HHX5HHH5HHH2511W9131M9290M5HH5HHH5HHH5HHH2B8H5HHH250900
BATERIA COMPLETA BATTERY ASSY (12N5.5-3B) YUASA TUBO (L550) HOSE (L550) TIRANTE DE BATERIA BAND, BATTERY CABLE CONDUCTOR POSITIVO WIRE, PLUS LEAD CABLE CONDUCTOR NEGATIVO WIRE, MINUS LEAD RECTIFICADOR Y REGULADOR RECTIFIER & REGULATOR ASSY TORNILLO DE CABEZA CON PLANA SCREW, PAN HEAD ARANDELA WASHER RELE COMPLETO RELAY ASSY CONJUNTO ARRANCADOR RELEVO STARTER RELAY ASSY.FUSIBLE (10A-BL).FUSE (10A-BL) PERNO, DE BRIDA BOLT, FLANGE CONJUNTO DE TRABAS LOCK ASSY.LLAVE DE IGNICION COMPLT.MAIN SWITCH STEERING LOCK CONJUNTO DE LLAVE IGNICION KEY, MAIN SWITCH PERNO BOLT ARANDELA WASHER INTERRUPTOR DE PARADA COMPLETO STOP SWITCH ASSY CONJUNTO DE CABLES WIRE HARNESS ASSY BRIDA CLAMP UNIDAD TRANSM. MED. COMBUST. SENDER UNIT ASSY, FUEL METER EMPAQUE DE UNIDAD TRANSMISORA GASKET, SENDER UNIT SEGURO RETAINER TORNILLO BOLT, FLANGE CABLE SUBCONDUCTOR WIRE, SUB LEAD

1 AP AP

FIG. 39 EQUIPO ELECTRICO 2

ELECTRICAL 2

1 5HHH9851M5HHH5HHH5HHH5HHH5HHH5HHH9580M23LH9570M90387067K9570M06500
BOBINA DE ENCENDIDO COMPLETA IGNITION COIL ASSY TORNILLO DE CABEZA CON PLANA SCREW, PAN HEAD TAPON DE BUJIA COMPLT PLUG CAP ASSY INTERRUPTOR NEUTRAL COMPL NEUTRAL SWITCH ASSY JUNTA GASKET UNIDAD C.D.I. COMPLETA C.D.I. UNIT ASSY BANDA BAND RELE DE DESTELLADOR COMPL. FLASHER RELAY ASSY BOCINA HORN TORNILLO BOLT, FLANGE REFLECTOR TRASERO COMPLETO REAR REFLECTOR ASSY TUERCA DE BRIDA NUT, FLANGE ESPACIADOR COLLAR ARANDELA PLANA WASHER, PLATE TUERCA DE BRIDA NUT, FLANGE
INDICE NUMERICO NUMERICAL INDEX
CODIGO N PART NO. 2UJ1113310 22F1113410 5RM1160700 4LS1163801 4LS1165102 4LS1168101 5HH1211300 22F1211600 22F1211702 22F1211801 2HX1211900 22F1215900 5VL1221010 4GL1332500 5RR1410100 5HH1410300 5DG1410600 5HH1410718 5HH1410A00 5HH1411225 4LS1412600 3SP1412800 4LS1413100 5K71413400 21V1414128 4KM1414215 5HH1414500 3H11414700 4LS1414700 4LS1415800 3SP1417900 24W1418400 5HH4LS1419100 3SP1419400 2AL1419600 4LS1419710 3SP1421600 6201423A70 3SP1426400 5HH5HH1490J00 5AP1492300 3H11496200 10V1564100 5HP1565100 REF. N CODIGO N PART NO. 5RE1611100 5AP1713100 5HH1715101 5AP1721100 5AP1724100 5HH1725101 22F22F2341201 5HH2592100 5HH8194002 12R8195001 42X8215100 5HH8253000 4NK8357E00 5RRE111110 5HHE111F00 5HHE116100 5HHE116600 5HHE116700 5HHE118100 5VLE118510 5HHE118600 5HHE13101035 5HHE135100 5HHE140020 5HHE142210 5HHE150002 5HHE153600 5RME160300 5RME160400 5RME160500 5RME160600 5HHE163100A0 5HHE163300 5HHE163509 5HHE163609 5HHE163709 5HHE211100 5HHE212100 5HHE215100 5HHE215610 5HHE217020 5VLE217610 5HHE221300 5HHE223110 5HHE224110 5HHE330000 REF. N CODIGO N PART NO. 5VLE332400 5HHE332900 5HHE341100 5HHE345100 5HHE356900 5HHE358600 5HHE441100 5HHE441200 5HHE441500 5HHE443700 5HHE443E01 5HHE445000 5HHE445100 5HHE445200 5HHE445300 5HHE445900 5HHE446100 5HHE446200 5HHE446210 5HHE461300 5HHE462800 5HHE470311 5HHE475800 5HHE515030 5HHE519100 5HHE536200 5HHE541101 5HHE541800 5HHE542100 5HHE544100 5HHE545100 5HHE546100 5VLE551200 5VLE551700 5HHE552100 5HHE553200 4FPE558000 5HHE559800 47VE561800 5VLE562000 5VLE566000 1B2E566600 5RME615000 5RME615400 5HHE616410 5HHE632100 5RME632400 5RME633300 REF. N CODIGO N PART NO. 5RME633700 5RME635100 5RME635600 5HHE635700 5RME635800 5RME637100 5RME637700 5HHE638110 5RME662800 5HHE712100 5HHE714100 5HHE722100 5HHE723100 5HHE740210 5HHE741110 4ANE745600 5HHE747100 5HHE810101 5HHE811000 5HHE811300 5HHE814000 5HHE818500 5HHE833700 5HHE851100 5HHE851200 5HHE851300 5HHE853100 5HHE853500 5HHE854000 5HHF11103033 5HHF13160033 5HHF13170033 5HHF13180033 5HHF137U20 5HHF137V20 5HHF137W2033 5HHF137W20P0 5HHF137W20P1 5HHF137W20P3 5HHF137X2033 5HHF137X20P0 5HHF137X20P1 5HHF137X20P3 2H3F139870 5HHF15110033 5HHF151100P7 5HHF151100P9 5HHF151100PA REF. N CODIGO N PART NO. 5HHF151300 5HHF151801 5LXF153E00 5LXF153E10 5LXF153E20 5HHF154100 5HHF161100 5HHF162100 5HHF168500 5HHF1711000Y 5HHF1711002Y 5HHF1711003Y 5HHF1711007X 5HHF1721000Y 5HHF1721002Y 5HHF1721003Y 5HHF1721007X 5LXF173E30 5LXF173E40 5LXF173E50 5LXF173E60 5LXF173F30 5LXF173F40 5LXF173F50 5LXF173F60 5HHF174600 5HHF177800 5HHF177G00 35NF178000 5HHF21101033 5HHF212300 5L9F212700 5HHF212800 5VLF214100 5HHF215100 5HHF221010 5HHF231110 5HHF310230 5HHF310330 5HHF310630 5HHF310730 5HHF311010 5VLF311100 REF. N CODIGO N PART NO. 5VLF311100 5HHF311810 5VLF314100 4GUF314400 4GUF314500 5APF314700 5APF315300 5APF316600 5VLF316800 5VLF317000 5HHF317411 5HHF317J00 5HHF334010 5LKF335600 5HHF338901 5HHF339500 5HHF341100 23LF341600 5HHF341800 4VWF341E00 5HHF341E00 5APF342700 5HHF34350033 3V9F34410033 4TUF347900 5LXF410040 5LXF410050 5LXF410060 5LXF410070 5HHF418100 5HHF418200 5HHF418300 5HHF421610 5LXF423500 5LXF424041 5LXF424051 REF. N 2 2