Transcript
RACING KART
OWNER’ S SERVICE MANUAL
7YP-28199-SE
NOTICE This manual was written by the Yamaha Motor Company primarily for use by Yamaha dealers and their qualified mechanics. It is not possible to put an entire mechanic's education into one manual, so it is assumed that persons using this book to perform maintenance and repairs on Yamaha racing kart have a basic understanding of the mechanical concepts and procedures inherent in racing kart repair technology. Without such knowledge, attempted repairs or service to this model may render it unfit to use and/or unsafe. Yamaha Motor Company, Ltd. is continually striving to improve all models manufactured by Yamaha. Modifications and significant changes in specifications or procedures will be forwarded to all Authorized Yamaha dealers and will, where applicable, appear in future editions of this manual.
PARTICULARY IMPORTANT INFORMATION This material is distinguished by the following notation. The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR SAFETY IS INVOLVED!
WARNING Failure to follow WARNING instructions could result in severe injury or death to the racing kart operator, a bystander, or a person inspecting or repairing the racing kart.
CAUTION:
A CAUTION indicates special precautions that must be taken to avoid damage to the racing kart.
NOTE:
A NOTE provides key information to make procedures easier or clearer.
KT100SEC/KT100SEJ OWNER'S SERVICE MANUAL ©2006 by Yamaha Motor Co., Ltd. 1st Edition, November 2006 All rights reserved. Any reprinting or unauthorized use without the written permission of Yamaha Motor Co., Ltd. is expressly prohibited.
HOW TO USE THIS MANUAL CONSTRUCTION OF THIS MANUAL This manual consists of chapters for the main categories of subjects. (See "Illustrated symbois") 1st title
This is a chapter with its symbol on the upper right of each page.
:
2nd title
:
This title appears on the upper of each page on the left of the chapter symbol. (For the chapter "Periodic inspection and adjustment" the 3rd title appears.)
3rd title
:
This is a final title.
MANUAL FORMAT All of the procedures in this manual are organized in a sequential, step-by-step format. The information has been compiled to provide the mechanic with an easy to read, handy reference that contains comprehensive explanations of all disassembly, repair, assembly, and inspections. IMPORTANT FEATURES Data and a special tool are framed in a box preceded by a relevant symbol . An encircled numeral indicates a part name. A condition of a faulty component will precede an arrow symbol and the course of action required the symbol . ●
●
●
EXPLODED DIAGRAM Each chapter provides exploded diagrams before each disassembly section for ease in indentifying correct disassembly and assembly procedures.
DISASSEMBLING THE ENGINE ENG
CHECKING THE ENGINE PARTS ENG
2. Remove: ●
CHECKING THE ENGINE PARTS
Bolt (crankcase)
INSTALLING THE CYLINDER HEAD 1. Inspect: ●
Carbon deposits Use a rounded scraper
CAUTION: Avoid scratching the aluminum. 3. Remove:
2. Inspect:
Right crankcase
Cylinder head warpage
●
Make sure the crank separating tool
●
body is
Warp limit
parallel with the crankcase.
0.015mm Out of specification → Replace
Crankcase separating tool: 90890-01135
CAUTION: Take care so that the oil seal lip is not damaged.
4. Remove: Left crankcase
●
Crankshaft assembly
●
Make sure the crank separating tool
body is
parallel with the crankcase. Crankcase separating tool 90890-01135
CAUTION: Take care so that the oil seal lip is not damaged.
REMOVING THE BEARING 1. Remove: Bearing
●
For removal of the bearing, two kinds of tools are available.
Choose the appropriate one
depending on how the bearing is installed. Fixed on the outside→Bearing puller Fixed on the inside → Bearing puller
4-8
4-9
GEN INFO
SPEC
ILLUSTRATED SYMBOLS (Refer to the illustration) GENERAL INFORMATION SPECIFICATIONS
INSP ADJ
ENG
REGULAR INSPECTION AND ADJUSTMENTS ENGINE CARBURETOR ELECTRICAL
CARB
ELEC Special tool Oil capacity Lubricant Tightening Specified value, Service limit Resistance (Ω), Voltage (V), Electric current (A) Engine speed
Apply engine mixing oil Apply lightweight lithium-soap base grease Apply locking agent (LOCTITE R ) Use new one
INDEX
GENERAL INFORMATION
SPECIFICATIONS REGULAR INSPECTION AND ADJUSTMENTS ENGINE
CARBURETOR
ELECTRICAL
GEN INFO
1
SPEC
2
INSP ADJ
3
ENG
4
CARB
5
ELEC
6
CONTENTS
REMOVING THE CLUTCH ･････････････････････････ 4-6
CHAPTER 1 GENERAL INFORMATION
REMOVING THE BEARING ････････････････････････ 4-8
INCLUDED PARTS････････････････････････････････ 1-1
CHECKING THE ENGINE PARTS ･･･････････ 4-9
SWITCH BRACKET ･････････････････････････････････ 1-1
CHECKING THE CYLINDER HEAD ･･･････････････ 4-9
INSTALLING THE BATTERY･･･････････････････････ 1-1
CHECKING THE CYLINDER ･････････････････････ 4-10
REMOVING THE CRANKSHAFT ･･････････････････ 4-7
STARTING ･･･････････････････････････････････････････ 1-2 STARTING THE ENGINE ･･･････････････････････････ 1-2
CHECKING THE PISTON AND PISTON PIN
CHECKING THE PISTON RING･･････････････････ 4-11 CHECKING THE PISTON CLEARANCE
CHAPTER 2 SPECIFICATIONS
･･･ 4-11
････････ 4-12
CHECKING THE CLUTCH ････････････････････････ 4-13
SPECIFICATIONS ････････････････････
ENGINE 2-1 ELECTRICAL SPECIFICATIONS･････････････ 2-2 TIGHTENING TORQUES ･･･････････････････････ 2-3
CHECKING THE GEAR1, 3 AND IDLE GEAR ･････ 4-14
2-3
CHECKING THE CRANKCASE BEARING ･･････ 4-14
2-3
CHECKING THE CRANKCASE OIL SEAL ･･････ 4-15
GENERAL TORQUE SPECIFICATIONS ･･････････ 2-3
CHECKING THE CRANKCASE ･･････････････････ 4-15
CABLE ROUTING DIAGRAM ･････････････････ 2-4
INSTALLING THE ENGINE ･･･････････････････ 4-16
ENGINE
･････････････････････････････････････････････
ELECTRICAL
･･･････････････････････････････････････
CHAPTER 3 REGULAR INSPECTION AND ADJUSTMENTS MAINTENANCE INTERVALS ･････････････････ 3-1 ENGINE ･･････････････････････････････････････････････ 3-3 ADJUSTING THE ENGINE IDLING SPEED
･･････
3-3
ADJUSTING THE THROTTLE PEDAL ････････････ 3-4
CHECKING THE STARTER MOTOR GEAR
････ 4-14
CHECKING THE CRANKSHAFT ･････････････････ 4-14
INSTALLING THE CRANKSHAFT ･･･････････････ 4-16 INSTALLING THE CRANKCASE ･････････････････ 4-17 INSTALLING THE PISTON RING AND PISTON････ 4-18 INSTALLING THE CYLINDER HEAD AND CYLINDER
･･･ 4-19
INSTALLING THE TCI MAGNETO ･･･････････････ 4-20 INSTALLING THE STARTER MOTOR ･･･････････ 4-20 INSTALLING THE CLUTCH ･･････････････････････ 4-21
ADJUSTING THE THROTTLE VALVE ･････････････ 3-4
ELECTRICAL ･･･････････････････････････････････････ 3-5 CHECKING THE
BATTERY ････････････････････････
CHECKING THE SPARK PLUG
･････････････････
3-5
3-10
TIGHTEN THE SPARK PLUG ････････････････････ 3-10 CHECKING THE IGNITION TIMING ･････････････ 3-11 ADJUSTING THE IGNITION TIMING ････････････ 3-11 ADJUSTING THE COIL GAP ･････････････････････ 3-12
CHAPTER 4 ENGINE
CHAPTER 5 CARBURETOR REMOVING AND DISASSEMBLY THE CARBURETOR ･･････････････････････････････ 5-1 SERVICE POINTS ･････････････････････････････････ 5-2 REMOVING AND DISASSEMBLY THE SL CARBURETOR ･････････････････････････ 5-3 SERVICE POINTS ･････････････････････････････････ 5-4 REMOVAL POINTS ･･･････････････････････････････ 5-5 REMOVING THE CARBURETOR･･････････････････ 5-5
EXPLODED DIAGRAM ･･････････････････････････ 4-1 ENGINE ･･････････････････････････････････････････････ 4-1 TCI MAGNETO ･･････････････････････････････････････ 4-2
CHECKING THE CARBURETOR ･･････････････････ 5-5 ASSEMBLING THE CARBURETOR･･･････････････ 5-5 INSTALLING THE CARBURETOR
････････････････ 5-6
STARTER MOTOR ･･････････････････････････････････ 4-2 SL CLUTCH ASSY ･･････････････････････････････････ 4-3
DISASSEMBLING THE ENGINE ･････････････ 4-4
CHAPTER 6 ELECTRICAL
REMOVING THE CYLINDER HEAD AND CYLINDER ････ 4-4
WIRING DIAGRAM ･･･････････････････････････････ 6-1 IGNITION SYSTEM ･･･････････････････････････････ 6-2
REMOVING THE PISTON AND PISTON RING･･･ 4-4
TROUBLESHOOTING ･･････････････････････････････ 6-2
･････････････ 4-5
STARTING SYSTEM ･････････････････････････････ 6-4
REMOVING THE TCI MAGNETO ･･････････････････ 4-5
TROUBLESHOOTING ･･････････････････････････････ 6-4
REMOVING THE STARTER MOTOR
GEN INCLUDED PARTS INFO
INCLUDED PARTS SWITCH BRACKET Install the switch stay between the steering wheel and its support.
1 Switch button side
138mm
INSTALLING THE BATTERY
4-φ6.5
1. Install: Battery box
122mm
●
113mm
2. Install: ●
Battery
3. Connect: ●
Battery lead
CAUTION: First, connect the positive lead negative lead
1-1
.
, then the
GEN STARTING INFO
STARTING STARTING THE ENGINE 1. Start the engine by pushing the start switch
.
If the engine fails to start by pushing the start switch
, release the switch, wait 30 seconds,
and then try again.
CAUTION: ● Do
not crank the engine more than 4 seconds
on any one attempt. For the protection of the starter motor and the prevention of the battery's over discharge, allow 30 seconds or more for engine restart. ● If
the engine is started in continued succession,
the battery may run out or the starter motor may be damaged.
2. When the engine is cold, cover the air box entrance lightly with the hand to choke off the air flow.
3. Stop the engine by pushing the stop switch. Continue pushing the engine stop button the engine comes to a stop.
1-2
till
ENGINE SPECIFICATIONS SPEC ENGINE SPECIFICATIONS Model name Specifications: Engine type Cylinder arrangement Displacement Bore × stroke Compression ratio Clutch type: Starting system Crank: Structure Big end bearing type Crankshaft: Small end free play “A”, Runout limit “B”, A Crank width “D” B
D
KT100SEC/KT100SEJ Air cooled 2-stroke, gasoline Single cylinder, forward inclined 0.0976L（97.6cm3） 52mm×46mm 7.9 Automatic Starter motor Assemble type Needle roller bearing
A: 0.1 mm or less B: 0.03 mm or less
B
C
D：45.8∼45.9mm
Piston: Piston to cylinder clearance Type End gap Carburetor: KT100SEC Type Standard setting Idle needle High speed needle Carburetor: KT100SEJ Type Standard setting Idle needle High speed needle Electrical: Ignition system Ignition system (BTDC) Coil: Primary winding resistance Secondary winding resistance Spark plug: Type manufacturer plug gap
0.030∼0.035mm Plain type (Cr-plated) 0.4∼0.5mm WALBRO WB-21 1-1/3±1/6 (80±10 min.) 5/12±1/6 （25±10 min.） WALBRO HDA237 1-1/4±1/6 (75 ±10 min.) 11/12 (55 min.) T.C.I 25°（2.6mm） 0.8∼1Ω 10KΩ B9EVX NGK 0.6∼0.7mm
2-1
2
ELECTRICAL SPECIFICATIONS SPEC ELECTRICAL SPECIFICATIONS Battery: Type manufacturer Operation voltage Rating
GT7B-4 GS yuasa 12V 6.5Ah
Starter motor: Type manufacturer Operation voltage Output
5M05-289 Mitsuba 12V 0.3kw
Starter relay: Type manufacturer Voltage rating Min. operation voltage Open voltage Coil resistance
B768042 Jideco DC12V (30 min.) DC8 V or less DC4 V or less 4.4Ω
2-2
TIGHTENING TORQUES SPEC TIGHTENING TORQUES ENGINE Part to be tightened Cylinder head Spark plug Crankcase Crankcase cover1 Crankcase cover2 Stay1 mounting bolt Gear3 mounting bolt Rotor mounting nut Cylinder Manifold mounting bolt Carburetor mounting Drive sprocket mounting Clutch stud bolt M8 stopper dowel
Thread size Thread Pitch diameter M8 M14 M6 M6 M5 M6 M5 M12 M8 M6 M6 M12 M12 M8
Q'ty 6 1 8 4 5 2 4 1 4 2 2 1 1 1
1.25 1.25 1.0 1.0 0.8 1.0 0.8 1.0 1.25 1.0 1.0 1.0 1.0 1.25
Tightening N・m（kg・m）
Remarks
18∼23（1.8∼2.3） 15∼25（1.5∼2.5） 10∼16（1.0∼1.6） YAMAHA Bond No. 1215 10∼16（1.0∼1.6） 6∼9 （0.6∼0.9） 10∼16（1.0∼1.6） 6∼9 （0.6∼0.9） 30∼40（3.0∼4.0） 18∼23（1.8∼2.3） 10∼16（1.0∼1.6） 7.5∼12（0.75∼1.2） ― 2.5 2.0
ELECTRICAL Part to be tightened Starter motor mounting bolt
Thread size Thread Pitch diameter M6
Q'ty
Tightening N・m（kg・m）
2
10∼16（1.0∼1.6）
1.0
GENERAL TORQUE SPECIFICATIONS
Thread size
This chart specifies torque for standard fasteners with standard I.S.O. pitch threads. Torque specifications for special components or assemblies are included in the applicable sections of this book. To avoid warpage, tighten multi-fastener assemblies in a crisscross fashion, in progressive stages, until full torque is reached. Unless otherwise specified, torque specifications call for clean, dry threads. Components should be at room temperature.
Distance across flats
M5 （ 8 mm）× P0 . 8 M6 （10mm）× P1 .0 M8 （13mm）× P1 . 25 M10 （14mm）× P1 . 5 M12 （17mm）× P1 . 5
Outside thread diameter
Pitch
2-3
Remarks
Tightening
0 . 4kg・m 0 . 6kg・m 1 . 5kg・m 3 . 0kg・m 5 . 5kg・m
CABLE ROUTING DIAGRAM SPEC CABLE ROUTING DIAGRAM Starter relay
Sub lead
Positive lead 1 (battery - starter relay)
Starter switch
Positive lead 2 (starter relay - starter motor)
Engine stop switch
Negative lead 1 (battery - coupler)
Fuel hose
Negative lead 2 (coupler - starter motor)
Throttle cable
2-4
INSP
MAINTENANCE INTERVALS ADJ MAINTENANCE INTERVALS
ENGINE
Item CYLINDER HEAD Inspect Clean Tightening PISTON Inspect Clean Measure Replace PISTON RING Inspect Replace PISTON PIN Inspect Replace PISTON PIN CLIP Inspect Replace SMALL END BEARING Inspect Replace CONNECTING ROD Inspect Replace BIG END BEARING Inspect Replace CRANK Inspect Measure Replace CRANK PIN Inspect Replace CRANK BEARING Inspect Replace OIL SEAL Inspect Replace CYLINDER Inspect Measure Replace
After Every Every Every Every As Storage break-in run race third fifth required (or 100 km) (or 300 km) (or 500 km)
○
○
○
○
○
○
○
(or 1000 km)
Remarks
○
Carbon deposits Tightening 1.8∼2.3kg･m
○ ○
Carbon deposits Piston clearance
○ ○
◎
○
◎
Replace the piston as a set.
○
◎
Replace the piston as a set.
○ ○
◎
Replace the piston as a set.
◎
Signs of heat discoloration. Replace the connecting rod as a set.
○
○
○
○
○
○ ○
○
○
◎
Free play exists. (1000 Laps later)
○
◎
Signs of heat discoloration. Replace the connecting rod as a set.
○
○ ○ ○
○ ○
Wear Round out Every season
○
Free play exists. Replace the connecting rod as a set.
○
○
Free play exists.
○ ○ ○
Oil leakage
○ ○
○
Score marks/wear Clearance/wear
○ ○ ○
3-1
3
INSP
MAINTENANCE INTERVALS ADJ Item CARBURETOR Inspect (Needle adjuster) (Metering lever)
ENGINE
Clean Tightening Replace (Nonmetal parts) SL carburetor air cleaner Clean CLUTCH Inspect Lubrication (CHAIN OIL) Replace (Clutch shoe) IDLE GEAR, GEAR 1,GIAR 3 Inspect Replace NEEDLE BEARING Inspect Replace BOLTS, NUTS Inspect Replace GASKETS Replace SPARK PLUG Inspect Clean Replace PLUG CAP Inspect Replace TCI MAGNETO Inspect Primary winding resistance Secondary winding resistance
After Every Every Every Every As Storage break-in run race third fifth required (or 100 km) (or 300 km) (or 500 km)
○ ○
(or 1000 km)
Standard position Bend/spring free length
○ ○
○
○ ○
○
○
Remarks
◎
Contamination/Dust Tightening 0.75∼1.2kg ･m Gaskets, o-rings
○ ○ ○
○ ○ ○ ○ ○ ○ ○
○
○ ○ ○
○
Never use using gaskets. Insulator color/Wear/Damage Carbon deposits
○ ○ ○
○
○ ○
○
○ ○ ○
3-2
Damage
INSP
ENGINE ADJ ENGINE
ADJUSTING THE ENGINE IDLING SPEED 1. Adjust: Idle needle Turning in the idle needle screw will lean out the mixture at low speeds, and turning out it will enrich the mixture.
●
Standard idle needle screw position SEC： 1-1/3±1/6 (80±10 min.) SEJ： 1-1/4±1/6 (75 ±10 min.) 2. Adjust: High speed needle Turning in the high speed needle screw will lean out the mixture at low speeds, and turning out it will enrich the mixture.
●
Standard high speed needle screw position SEC： 5/12±1/6 (25±10 min.) SEJ： 11/12 (55 min.) 3. The engine is warmed up 4. Attach: Engine speed meter Connect the engine speed meter clip as shown.
●
Engine speed meter 90890-03113
5. Adjust: Idle adjust screw Turning in the idle adjust screw will increase idle speed, and turning out it will decrease idle speed.
●
Standard engine idling speed: 3000∼3800rpm
WARNING Before starting the engine, be sure to use the
※The photos and illustration show SEC model.
kartstand for safety.
3-3
INSP
ENGINE ADJ
ADJUSTING THE THROTTLE PEDAL 1. Inspect: ●
Throttle pedal free play Throttle pedal free play 2∼5mm
Out of specification → Adjust.
2. Adjust: ●
Throttle pedal free play
Loosen the locknut
and turn the adjuster ･
in fully.
3. Adjust: ●
Throttle pedal free play
Loosen the locknut ･ and adjust the adjuster ･ .
ADJUSTING THE THROTTLE VALVE 1. Inspect: ●
Throttle valve
Check whether the throttle valve is fully open when the throttle pedal is depressed for a full stroke.
2. Adjust: ●
Locknut
●
Adjuster
Loosen the locknut and adjust the adjuster.
NOTE: After adjusting the throttle valve, the throttle pedal should be adjusted.
3-4
INSP
ELECTRICAL ADJ ELECTRICAL CHECKING 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: ● Charge ● Keep
batteries in a well-ventilated area.
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.
CAUTION: ● Charging
time,
charging
amperage
and
charging voltage for an MF battery are different from those of conventional batteries. ● The
MF battery should be charged as explained
in the charging method illustrations. ● If
the battery is overcharged, the electrolyte
level will drop considerably. Therefore, take special care when charging the battery.
3-5
INSP
ELECTRICAL ADJ NOTE:
Since MF batteries are sealed, it is not possible to check the charge state of the battery by measuring the specific gravity of the electrolyte. Therefore, the charge of the battery has to be checked by measuring the voltage at the battery terminals.
1. Remove: ●
Battery lead
(from battery terminal)
CAUTION: First, disconnect the negative battery lead and then the positive battery lead
,
.
2. Remove: ●
Battery
3. Measure: ●
Battery charge
a. Connect the digital circuit tester
to the
battery terminals. Digital circuit tester 90890-03174 ●
Tester positive probe →Battery positive terminal
●
Tester negative probe →Battery negative terminal
3-6
INSP
ELECTRICAL ADJ NOTE: ● The
charge state of an MF battery can be
checked by measuring its open-circuit voltage (i.e., the voltage when the positive terminal is disconnected). ● No
charging is necessary when the open-
circuit voltage equals or exceeds 12.8 V. b. Check the charge of the battery, as shown in Open-circuit voltage
the charts and the following example. 13.0
Example 12.5
c. Open-circuit voltage = 12.0 V
12.0
d. Charging time = 6.5 hours
11.5
e. Charge of the battery = 20 ∼ 30% 5
6.5
10 hr.
Open-circuit voltage
Charging time (hours)
Ambient temperature 20 ° C (68 ° F)
13 12
11
10
100
75
50
30 25 20
0
Charging condition of the battery
4. Charge: ●
Battery
WARNING Do not quick charge a battery. (refer to the appropriate charging method illustration) Use the specified current and voltage for a refreshing charge. Charging current and charging time 0.65 A ×10 hours Completed charging voltage 12.8 V or more
3-7
INSP
ELECTRICAL ADJ CAUTION: ● Never ● Do
remove the MF battery sealing caps.
not use a high-rate battery charger since it
forces a high-amperage current into the battery quickly and can cause battery overheating and battery plate. ● If
it is impossible to regulate the charging
current on the battery charger, be careful not to overcharge the battery. ● When
charging a battery, be sure to remove it
from the machine. (If charging has to be done with the battery mounted on the machine, disconnect the negative battery lead from the battery terminal.) ● To
reduce the chance of sparks, do not plug in
the battery charger until the battery charger leads are connected to the battery. ● Before
removing the battery charger lead clips
from the battery terminals, be sure to turn off the battery charger. ● Make
sure the battery charger lead clips are in
full contact with the battery terminal and that they are not shorted. A corroded battery charger lead clip may generate heat in the contact area and a weak clip spring may cause sparks. ● If
the battery becomes hot to the touch at any
time during the charging process, disconnect the battery charger and let the battery cool before reconnecting it. Hot batteries can explode! ● As
shown in the following illustration, the open-
circuit voltage of an MF battery stabilizes about Charging
30 minutes after charging has been completed.
Charging time 20℃
Open-circuit voltage
18
Therefore, wait 30 minutes after charging is
17
completed before measuring the open-circuit
16 15
voltage.
14 13 12 11 10
0
10
20
30
40 50 60 Charging time Check the (minutes) open-circuit voltage
3-8
INSP
ELECTRICAL ADJ 5. Inspect: ●
Battery terminal
Dirt → Clean with wire brush Loose → Connect 6. Apply the grease. ●
Battery terminal
7. Install: ●
Battery
8. Connect: ●
Battery lead
(to battery terminal)
CAUTION: First, connect the positive lead negative lead
3-9
.
, then the
INSP
ELECTRICAL ADJ CHECKING THE SPARK PLUG
NOTE: Remove a mud and dust from the cylinder head before removing the spark plug. 1. Inspect: ●
Electrode
Wear/Damage → Replace. Dirt/Carbon deposit → Clean the spark plug with a spark plug cleaner or wire brush. Wear/Damage → Replace. ●
plug gap
Out of specification → Regap. Spark plug gap Standard spark plug 0.6∼0.7mm
Manufacturer
B9EVX
NGK
CAUTION: Do not run the kart with a plug gap larger than the specified value.
NOTE: When the engine runs for many hours at low speeds, the spark plug insulator will become sooty, even if the engine and carburetor are in good operating condition.
TIGHTEN THE SPARK PLUG
CAUTION: Do not tighten the spark plug with a plug wrench from the start. It may damage the screw thread in the cylinder head. ●
Finger-tighten
to specification
the spark plug before torquing .
Spark plug 1.5∼2.5kg・m
NOTE: ● Before
installing the spark plug, clean the
gasket surface and plug surface. ● Do
not tighten the plug above the specified
torque.
3-10
INSP
ELECTRICAL ADJ CHECKING THE IGNITION TIMING 1. Remove: ●
Spark plug
●
Crankcase cover2
●
Gear3
●
Stay1
2. Attach: ●
Dial gauge stand set Dial gauge stand set 90890-01252
3. Rotate the rotor
counter clockwise until the
piston reaches top dead center (TDC). When this happens, the needle on the dial gauge will stop and reverse directions even though the rotor is being turned in the same direction. 4. Set the dial gauge to zero at TDC. 5. From TDC, rotate the rotor clockwise until the dial gauge indicates that the piston is at "2.6 mm" from TDC. 6. Check: ●
Ignition timing
Punch mark punch mark
on rotor should be aligned with on stator.
Not aligned → Adjust. ADUSTING THE IGNITION TIMING 1. From TDC, rotate the rotor
clockwise until
the dial gauge indicates that the piston is at "2.6 mm" from TDC. 2. Loosen the plate mounting bolts punch marks by turning the stator 3. Tighten: ●
Plate mounting bolt
4. Install: ●
Stay1
●
Gear3
●
Crankcase cover2
●
Spark plug Spark plug 1.5∼2.5kg・m
3-11
and align the .
INSP
ELECTRICAL ADJ ADJUSTING THE COIL GAP 1. Remove: ●
Crankcase cover2
●
Gear3
●
Stay1
2. Measure the air gap
between the rotor ･
and coil assembly Standard air gap 0.4mm Out of specification → Adjust. 3. Adjust: ●
Air gap
Loosen the coil assembly mounting bolts move the pick-up coil assembly specified gap is obtained. 4. Tighten: ●
Coil assembly mounting bolt
5. Install:
3-12
●
Stay1
●
Gear3
●
Crankcase cover2
and
until the
EXPLODED DIAGRAM ENG EXPLODED DIAGRAM ENGINE
Bearing
Crankcase (L, R)
Cylinder head
Oil seal
Joint pipe
Cylinder head gasket
Small end bearing
Drive sprocket
Spark plug
Piston pin
Nut
Cylinder
Piston
Absorber A
Cylinder gasket
Piston ring
Absorber B
Crank assembly
Piston pin clip
4
4-1
EXPLODED DIAGRAM ENG TCI MAGNETO
STARTER MOTOR
Rotor
Engine starter switch
Crankcase cover1
Gear1
Coil assembly
Engine stop switch
Crankcase cover2
Needle bearing
Nut
Lead wire
Starter motor
Bearing
Idle gear
Gear3
Needle bearing
Stay1
Plate
T.
R. T.
R.
T.
R. T.
R. T.
R.
T.
R. T.
R.
4-2
EXPLODED DIAGRAM ENG SL CLUTCH ASSY Circlip (seeger ring)
Stud bolt (adapter shaft)
Spacer
Thrust washer (shim)
Sprocket Z10
Clutch body
Sprocket Z11
Key (woodruff key)
M5 screw
Clutch cover
Clutch drum
Chain guard
Roller gauge M8 stopper screw (stop dowel)
4-3
DISASSEMBLING THE ENGINE ENG DISASSEMBLING THE ENGINE REMOVING THE CYLINDER HEAD AND CYLINDER 1. Remove: ●
Spark plug
●
Cylinder head mounting nut
●
Cylinder head
2. Remove: ●
Cylinder head gasket
●
Cylinder mounting nut
●
Cylinder
●
Cylinder gasket
REMOVING THE PISTON AND PISTON RING 1. Remove: ●
Piston pin clip
●
Piston pin
●
Piston
CAUTION: ●
Before removing piston pin clip, cover crankcase with a clean rag to prevent piston pin clip from falling into crankcase cavity.
● Before
removing the piston pin，deburr the
clip groove and pin hole area．If the piston pin groove is deburred and piston pin is still difficult to remove，use the piston pin puller ●
.
Do not use a hammer to drive the piston. Piston pin puller: 90890-01304
2. Remove: ●
4-4
Small end bearing
DISASSEMBLING THE ENGINE ENG 3. Remove: Piston ring While opening its meeting ends, remove the piston ring on the side opposite to them.
●
CAUTION: Take care not to scratch the piston or damage the piston ring by expanding it more than necessary.
REMOVING THE STARTER MOTOR 1. Remove: ●
Crankcase cover2 mounting bolt
●
Crankcase cover2
2. Remove: ●
Stay1 mounting bolt
●
Stay1
●
Gear3 mounting bolt
●
Gear3
●
Gear1
●
Idle gear
3. Remove: ●
Crankcase cover1 mounting bolt
●
Crankcase cover1
●
Starter motor mounting bolt
●
Starter motor
REMOVING THE TCI MAGNETO 1. Remove: ●
4-5
Rotor nut
DISASSEMBLING THE ENGINE ENG 2. Remove: ●
Rotor
When removing the rotor, use the rotor puller
.
Rotor puller 90890-01362
CAUTION: Take care not to screw in the two bolts of the rotor puller too far.
They may contact the
stator and damage it. 3. Remove: ●
Plate mounting bolt
●
Plate
REMOVING THE CLUTCH 1. Remove: ●
Circlip (seeger ring)
●
Spacer
2. Remove: ●
Clutch drum
3. Remove:
4-6
●
Roller gauge
●
Thrust washer (shim)
DISASSEMBLING THE ENGINE ENG 4. Loosen: ●
M8 stopper screw (stop dowel)
●
Stud bolt (adapter shaft)
5. Remove: ●
Clutch body
Reference For removal, use the specialized tool.
6. Remove: ●
Key (woodruff key)
REMOVING THE CRANKSHAFT 1. Remove:
4-7
●
Engine bracket mounting bolt
●
Engine bracket
DISASSEMBLING THE ENGINE ENG 2. Remove: ●
Bolt (crankcase)
3. Remove: ●
Right crankcase
Make sure the crank separating tool
body is
parallel with the crankcase. Crankcase separating tool: 90890-01135
CAUTION: Take care so that the oil seal lip is not damaged.
4. Remove: ●
Left crankcase
●
Crankshaft assembly
Make sure the crank separating tool
body is
parallel with the crankcase. Crankcase separating tool 90890-01135
CAUTION: Take care so that the oil seal lip is not damaged.
REMOVING THE BEARING 1. Remove: ●
Bearing
For removal of the bearing, two kinds of tools are available.
Choose the appropriate one
depending on how the bearing is installed. Fixed on the outside→Bearing puller Fixed on the inside → Bearing puller
4-8
CHECKING THE ENGINE PARTS ENG CHECKING THE ENGINE PARTS CHECKING THE CYLINDER HEAD 1. Inspect: ●
Carbon deposits
Use a rounded scraper
CAUTION: Avoid scratching the aluminum. 2. Measure: ●
Cylinder head warpage Warp limit 0.015mm
Out of specification → Replace
4-9
CHECKING THE ENGINE PARTS ENG CHECKING THE CYLINDER 1. Inspect: ●
Exhaust port carbon deposition
Use a rounded scraper
.
CAUTION: Avoid scratching the aluminum.
2. Inspect: ●
Cylinder wall
Score marks → Repair. Use #400∼600 grit wet sandpaper. Damage → Rebore or Replace.
3. Measure: ●
Cylinder wall wear
Measure the cylinder bore in parallel to and at right angles to the crankshaft. Then, find the average of the measurements. Cylinder wall wear
＝
(Maximum (Minimum − Aa∼Cb) Aa∼Cb)
Wear limit 0.015mm Out of specification → Rebore or replace. Cylinder bore gauge 90890-03017
4-10
CHECKING THE ENGINE PARTS ENG CHECKING THE PISTON AND PISTON PIN 1. Inspect: ●
Piston crown
carbon deposits
Use a scraper. ●
Ring groove
carbon deposits
Use a used piston ring. Wear/Scratches/Damage → Replace.
2. Measure: ●
Piston diameter
Micrometer 10 mm (0.39 in) from the piston bottom edge. Standard piston diameter 51.970∼51.990mm
3. Check: ●
Free play (When the piston pin
in the piston
is in place
.)
There should be no noticeable for the play. Free play exists → Replace piston pin and/or piston.
4. Inspect: ●
Check the free play when the piston pin
bearing
and
are in place in the connecting rod.
Free play exists → Replace piston pin and/or small end bearing.
CHECKING THE PISTON RING 1. Measure: ●
End gap
Thickness gauge Insert a ring into the cylinder and push it approximately 10 mm (0.39 in) into the cylinder. End gap limit 0.5mm Out of specification → Replace
4-11
; ;; ;
CHECKING THE ENGINE PARTS ENG CHECKING THE PISTON CLEARANCE
Cylinder
Feeler gauge
●
Method to use a feeler gauge.
Feeler gauge How to insert the piston and the feeler gauge
Piston
is as shown: The piston pin is inserted in parallel with the crankshaft axis. Optimum piston clearance is evaluated by smoothness of drawing out the feeler gauge. ●
Calculate the piston-to -cylinder clearance with
following formula. PISTON CYLINDER PISTON ＝ − CLEARANCE BORE DIAMETER
* Refer to the following sections for inspection method: CHECKING THE CYLINDER and CHECKING THE PISTON AND PISTON PIN. Standard piston-to-cylinder clearance 0.030∼0.035mm
CAUTION: ● If
out of specification, rebore or replace
cylinder, and replace piston and piston rings as a set. ● If
the piston clearance is over specification,
rebore cylinder and replace piston with oversized piston to meet the specification. ● If
piston is replaced with oversized piston,
piston ring should be replaced with the equivalent oversized piston ring. Piston size number Piston diameter(mm) Piston ring size number
1 2 3 4 5 6 7 8 9 10 11 12
4-12
52.00 52.05 52.10 52.15 52.20 52.25 52.30 52.35 52.40 52.45 52.50 52.55
1 2 3 4 5 6 7 8 9 10 11 12
CHECKING THE ENGINE PARTS ENG CHECKING THE CLUTCH 1. Inspect: ●
Clutch drum
●
Clutch body
Wear/Scratch/Damage → Replace.
2. Inspect: ●
Drive sprocket
Wear/Damage → Replace the clutch drum.
3. Inspect: ●
Clutch shoe thickness Standard shoe thickness 3.3mm Wear limit 1mm
●
Roller gauge
Wear/Damage → Replace. 4. Inspect the other parts. Wear/Damage → Replace.
4-13
CHECKING THE ENGINE PARTS ENG CHECKING THE GEAR1, 3 AND IDLE GEAR 1. Inspect: ●
Gear1
●
Gear3
●
Idle gear
Wear/Damage → Replace.
CHECKING THE STARTER MOTOR GEAR 1. Inspect: ●
Starter motor gear
Wear/Damage → Replace.
CHECKING THE CRANKSHAFT 1. Measure: ●
Small end free play
Out of specification → Replace the connecting rod, crank pin and bearing. ●
Crankshaft runout
Out of specification → Repair or replace. ●
Crank width
Out of specification → Repair or replace. Standard
Limit
Small end free play
―
1.0mm
Runout
―
0.03mm
Crank width
45.8∼45.9mm
―
CHECKING THE CRANKCASE BEARING 1. Inspect: ●
Crankshaft bearing
Rough spot/seizure → Replace.
4-14
CHECKING THE ENGINE PARTS ENG CHECKING THE CRANKCASE OIL SEAL 1. Inspect: ●
Oil seal
Wear/Damage → Replace.
CHECKING THE CRANKCASE 1. Inspect: ●
Right crankcase
●
Left crankcase
Wear → Repair. Use #400∼600 grit wet sandpaper.
4-15
INSTALLING THE ENGINE ENG INSTALLING THE ENGINE INSTALLING THE CRANKSHAFT 1. Install: ●
Crankshaft bearing
Install the bearing by pressing it on the side having the manufacture's marks or numbers.
NOTE: Install the bearing with its outer race 0.5mm above the crank case surface.
2. Install: ●
Oil seal
CAUTION: Install the oil seal by pressing its outer race parallel.
Oil seal
4-16
INSTALLING THE ENGINE ENG INSTALLING THE CRANKCASE 1. Clean the contacting surface of crankcase (left and right) before applying the sealant. 2. Install: ●
Dowel pin
3. Install: ●
Right crankcase
●
Crankshaft
Install the crankshaft by installing tools. Crankshaft installing pot 90890-01274 Crankshaft installing bolt 90890-01275 Adapter 90890-01278
CAUTION: Take care so that the oil seal lip is not damaged.
4. Apply the sealant. ●
4-17
Left crankcase
INSTALLING THE ENGINE ENG 5. Install: ●
Crankcase mounting bolt
Tighten all bolts in 2∼3 steps and be sure to tighten in numbered order as shown. Crankcase mounting bolt 1.0∼1.6kg・m
6. Install: ●
Engine bracket Engine bracket mounting bolt 2.5∼3.0kg・m
INSTALLING THE PISTON RING AND PISTON 1. Install: ●
Piston ring
Align the piston ring mark gap with the pin
upward and its
. After installing the piston
ring, check for smooth movement.
CAUTION: Take care not to scratch the piston or damage the piston ring.
2. Install: ●
Small end bearing
Apply the engine oil onto the small end and big end bearings.
4-18
INSTALLING THE ENGINE ENG 3. Install: ●
Piston
●
Piston pin
●
Piston pin clip
The arrow
on the piston dome must point
to exhaust side. Piston pin clip
NOTE: ● Before
installing the piston pin clip, cover the
crankcase with a clean rag to prevent the piston pin clip from falling into the crankcase cavity. ● Never
force to insert.
INSTALLING THE CYLINDER HEAD AND CYLINDER 1. Apply the engine oil to the piston, piston ring and piston pin.
2. Install: ●
Cylinder gasket
●
Cylinder
NOTE: ● Apply
the engine oil onto the cylinder inner
surface. ● Make
sure the piston ring is properly positioned.
Install the cylinder with one hand while compressing the piston ring with the other hand. ●
After installing, check the smooth movement of the piston. Cylinder 1.8∼2.3kg・m
3. Install: ●
4-19
Cylinder head gasket
INSTALLING THE ENGINE ENG 4. Install: ●
Cylinder head Cylinder head 1.8∼2.3kg・m Tighten all bolts in 2∼3 steps and be sure to tighten in numbered order as shown.
INSTALLING THE TCI MAGNETO 1. Temporarily install: ●
Plate
2.install: ●
Woodruff key
●
Rotor
When installing the rotor, align the keyway of the rotor with the woodruff key. 3. Install: ●
Rotor nut Rotor nut 3.0∼4.0kg・m
4. Adjust the ignition timing. (Refer to the CHAPTER 3.) 5. Tighten the plate.
6. Temporarily install: ●
Coil assembly
7. Adjust the air gap
and tighten the coil assembly.
Air gap 0.4mm
INSTALLING THE STARTER MOTOR 1. Install the starter motor to the crankcase cover1 ●
Starter motor mounting bolt
●
Starter motor
2. Install:
4-20
●
Crankcase cover1 mounting bolt
●
Crankcase cover1
.
INSTALLING THE ENGINE ENG 2. Install: ●
Stay1 mounting bolt
●
Stay1
●
Gear3 mounting bolt
●
Gear3
●
Gear1
●
Idle gear
3. Install: ●
Crankcase cover2 mounting bolt
●
Crankcase cover
INSTALLING THE CLUTCH 1. Install: ●
Key (woodruff key)
2. Install: ●
Clutch body
CAUTION: ● Install
the clutch body while taking note of
its direction.
3. Install: ●
Stud bolt (adapter shaft)
Apply locking agent (LOCTITE
R
)
Stud bolt (adapter shaft) 2.5kg・m Reference For installation, use the specialized tool.
4-21
INSTALLING THE ENGINE ENG 4. Tighten: ●
M8 stopper screw (stop dowel)
Apply locking agent (LOCTITE
R
)
M8 stopper screw (stop dowel) 2.0kg・m
5. Tighten: ●
Thrust washer (shim)
●
Roller gauge
Apply the grease onto the roller gauge.
6. Install: ●
Clutch drum
CAUTION: After installing the clutch drum, check for smooth movement.
7. Install:
4-22
●
Spacer
●
Circlip (seeger ring)
ENG
4-23
CARBURETOR CARB REMOVING AND DISASSEMBLY THE CARBURETOR Preparation for removal ● ●
Remove the air box. Remove the throttle cable.
● ●
Remove the fuel hose. Remove the pulse hose.
5-1
CARBURETOR CARB SERVICE POINTS ●
Clean the removing parts before inspecting.
Extent of removal REMOVING THE CARBURETOR
REMOVING THE METERING DIAPHRAGM
REMOVING THE INLET NEEDLE VALVE
REMOVING THE PUMP DIAPHRAGM
Extent of removal Order
Parts name Nut Washer Air box joint1 Gasket Carburetor assembly Gasket Screw Cover Metering diaphragm Gasket Screw Circuit plate Diaphragm Gasket Screw Pin Metering lever Spring Inlet needle valve Screw Cover Gasket Pump diaphragm High speed needle Spring Washer O-ring Idle needle Spring Ring Screw Throttle valve Throttle shaft Spring Screw Choke valve Choke shaft
Q'ty 2 2 1 1 1 1 4 1 1 1 2 1 1 1 1 1 1 1 1 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
5-2
Remarks
5
SL CARBURETOR CARB REMOVING AND DISASSEMBLY THE SL CARBURETOR Preparation for removal ● ●
Remove the air box. Remove the throttle cable.
● ●
Remove the fuel hose. Remove the pulse hose.
5-3
SL CARBURETOR CARB SERVICE POINTS ●
Clean the removing parts before inspecting.
Order
Parts name
Q'ty
Bolt Manifold Gasket Carburetor assembly Screw Pump cover Pump gasket Pump diaphragm Metering diaphragm gasket Diaphragm assembly Metering diaphragm cover Screw Inlet needle valve Metering lever pin Metering lever Spring Screw Spring Idle adjust screw Spring High speed needle Spring Idle speed needle Throttle shaft assembly Spring Throttle valve Screw Throttle stopper Screw
2 1 1 1 1 1 1 1 1 1 1 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
5-4
Remarks
CARBURETOR CARB REMOVAL POINTS REMOVING THE CARBURETOR 1. Disconnect: ●
Fuel hose
●
Negative pressure hose
●
Throttle cable
WARNING Plug the fuel hose so that fuel does not run out.
NOTE: Always clean up spilled fuel immediately. 2. Remove: ●
Air box
●
Carburetor
CHECKING THE CARBURETOR 1. Inspect: ●
Float chamber body
Blow out all passages and jets with compressed air.
CAUTION: Never use a wire.
ASSEMBLING THE CARBURETOR 1. Inspect: ●
Metering lever distance Standard metering lever distance 0.13∼0.25mm
Out of specification → Adjust.
2. Adjust: ●
Metering lever
Bend the rib of the metering lever
5-5
.
CARBURETOR CARB INSTALLING THE CARBURETOR 1. Install: ●
Carburetor
●
Air box
●
Hose clamp Carburetor gasket
2. Connect: ●
Throttle cable
●
Fuel hose
●
Negative pressure hose
3. Adjust:
5-6
●
Throttle pedal free play
●
Engine idling speed
WIRING DIAGRAM ELEC WIRING DIAGRAM
Engine stop switch
Engine starter switch
White/Black Black Black Black
White/Black Black Black Blue
White/Black Red Blue Red
Black
Black Red Battery
TCI unit Starter relay
Red Black
Red Black Starter motor Earth
6-1
IGNITION SYSTEM ELEC TROUBLESHOOTING
1. Spark plug
NO SPARK
●
Spark plug condition
INTERMITTENT SPARK
●
Spark plug type
●
Spark plug gap
Check
Refer to the CHAPTER 3.
1. Spark plug
Standard spark plug
2. Minimum spark gap
B9EVX（NGK）
3. Engine stop switch
Spark plug gap
4. Primary coil resistance
0.6∼0.7mm
5. Secondary coil resistance OK
6. Wiring (Ignition system)
INCORRECT
NOTE:
Repair or replace the
Use the following special tool(s) in this
spark plug.
troubleshooting. 2.Minimum spark gap
Pocket tester
Disconnect the spark plug cap
90890-03112
from spark
plug. Connect the ignition checker (dynamic
Ignition checker
spark tester)
90890-06754
as shown. Turn the crank and
measure the ignition spark gap. Minimum spark gap 6mm
6 OK
Ignition system is good. Check the fuel system, engine or carburetor.
6-2
INCORRECT
IGNITION SYSTEM ELEC 3. Engine stop switch ●
5. Secondary coil resistance
Check the engine stop switch for continuity.
●
Disconnect the high tension lead from the spark plug.
CONTINUITY
NO CONTINUITY
●
high tension lead.
Replace the engine stop switch.
●
Connect the pocket tester (x1kΩ) to the ignition coil.
●
Tester
lead → Black terminal
●
Tester
lead → High tension lead
4. Primary coil resistance ●
Disconnect the spark plug cap from the
Secondary coil resistance
Disconnect the ignition coil lead from the
10k Ω（×kΩ）
engine stop switch lead. ●
OK
NO
Connect the pocket tester (x1Ω) to the ignition coil.
Replace the ignition
●
Tester
lead → Black terminal
●
Tester
lead → Ground to coil body
coil.
6. Wiring ●
Check the entire ignition system for connections. Refer to "WIRING DIAGRAM" section in the CHAPTER 6. OK
Replace the rotor.
Primary coil resistance
Properly connect or repair the ignition
0.8∼1.0 Ω（×1Ω） OK
NO
system's wiring.
NO
Replace the ignition coil.
6-3
STARTING SYSTEM ELEC 2. Starter motor
TROUBLESHOOTING
●
If the starter motor will not operate.
Connect the positive battery terminal starter motor lead
and
with a jumper lead
.
Check Red
1. Battery 2. Starter motor
Red
3. Starter relay 4. Engine starter switch
Black
5. Wiring
Black
NOTE:
WARNING
Use the following special tool(s) in this
●A
troubleshooting.
wire that is used as a jumper lead must
have at least the same capacity or more as that of the battery lead, otherwise the
Pocket tester:
jumper lead may burn.
90890-03112
● This
check is likely to produce sparks,
therefore make sure nothing flammable is in the vicinity.
1. Battery ●
Battery condition
●
Refer to the CHAPTER 3.
Dose the starter motor turn ? YES
NO
Open circuit voltage 12.8 V or more at 20 C° OK
Repair or replace the
NO
●
Clean the battery terminal.
●
Recharge or replace the
starter motor.
battery.
6-4
STARTING SYSTEM ELEC 4. Engine starter switch
3. Starter relay ●
Disconnect the starter relay coupler from
●
Check the engine starter switch for continuity.
sub lead wire. ●
CONTINUITY
Connect the pocket tester (x1Ω) and the battery to the starter relay as shown.
Battery
terminal → Terminal2
Battery
terminal → Terminal4
Tester
lead → Terminal1
Tester
lead → Terminal3
NO CONTINUITY Replace the engine starter switch.
5. Wiring ●
Check the entire starting system for connections. Refer to "WIRING DIAGRAM" section in the CHAPTER 6.
12V OK ●
NO
Does the starter relay have continuity between terminal 1 and 3 ? YES
NO
Starting system is
Properly connect or
correct.
repair the starting system's wiring.
Replace the starter relay.
6-5
YAMAHA MOTOR CO., LTD.
PRINTED ON RECYCLED PAPER
PRINTED IN JAPAN (E)
