SCOOTER SERVICE MANUAL
KEEWAY 50cc Models
© KEEWAY AMERICA, LLC
SPRING 2008
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If problems cannot be resolved or further assistance is needed,
please feel free to contact us.
KEEWAY AMERICA, LLC
2912 SKYWAY CIRCLE N.
IRVING, TX 75038
214-441-9661 PHONE
214-441-9641 FAX
service@keeway-america.com
Our support staff will assist in any way possible.
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PRE-DELIVERY INSPECTION
In order for KEEWAY America to maintain its high standards of quality, it is necessary
for each dealer to thoroughly inspect each unit before their customer takes delivery.
INITIAL:
Wash entire vehicle with warm water and wipe dry with a soft cloth. DO NOT
USE SOAP OR TERRY CLOTH.
Inspect paint sheen and decal quality.
Ensure all fasteners have appropriate torque, to include visible body screws, axle
and exhaust nuts, engine and carburetor bolts, etc.
Ensure proper operation of all lock cylinders.
Verify that a new, fully charged battery has been installed.
Inspect vehicle electrical system, including switch and control operations.
Ensure proper operation and adjustment of levers, throttle and rear brake cables.
Ensure proper front and rear brake operation, including fluid level, and adjust as
needed.
Verify spark plug gap, and adjust accordingly.
Start engine and bring to operating temperature. Check fluid levels, and add if
necessary.
Check and adjust idle speed as needed.
Ensure free travel of both wheels.
Check tire pressure, and adjust accordingly.
Verify proper operation of remote-start system.
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TEST DRIVE:
Verify proper front and rear suspension for correct damping and travel.
Ensure proper operation and settings of gauge cluster.
Verify wheel alignment, and adjust accordingly.
Check for fluid leaks, and adjust levels accordingly.
Verify proper operation and adjustment of all vehicle lights.
FINAL:
Wipe down entire vehicle with soft cloth to remove any dust or debris.
Detail grips, seat, and tires.
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MAINTENANCE CHART
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TABLE OF CONTENTS__________________________
PREDELIVERY INSPECTION
MAINTENANCE CHART
PREFACE
KEEWAY SERVICE GUIDELINES
ELECTRICAL PRECAUTIONS
SAFETY GUIDELINES
SPECIALTY TOOLS REQUIRED
GENERAL INFORMATION
Terminology
The 2-Stroke Engine Cycle
Vehicle Information
General Specifications
POWERTRAIN SPECIFICATIONS
Fastener Torque
DIMENSIONS
Alignment Pins/Dowels
Pin shafts
O-rings
Seals
Bearings
Gaskets
Gears
Sprockets
Chains
ENGINE PARTS ORIENTATION
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ENGINE COMPONENT FIT/TOLERANCE
Cylinder Head/Valve
Cylinder Jug/Piston
SYSTEM FUNDAMENTALS
Kick Start Chain Reaction
Fuel Delivery System
Brake System Fundamentals
Fundamental Front Absorber Theory
TROUBLESHOOTING AND PROCEDURES
COMMON ISSUES
Electric Starter Doesn’t Engage or Rotate
Only Clicking Noise When Starter Button Is Pressed
No Reaction Whatsoever When Starter Button Is Pressed
Hard Start/Poor Idle/Poor Performance
No Start
Insufficient Power/Lack of Acceleration
Poor/Difficult Handling/Instability
Soft Brakes or Too Much Lever Travel
Hard Brakes or Stiff Lever Feel
BATTERY/CHARGING SYSTEM FUNDAMENTAL TEST
ENGINE COMPRESSION TEST
IGNITION TIMING TEST
TECHNICAL GUIDE FOR 50cc CARBURETORS
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POWERTRAIN COMPONENTS
CARBURETOR REMOVAL/INSTALLATION
ENGINE AND COMPONENTS REMOVAL/INSTALLATION
Cowling Assembly
Cylinder Head Assembly
Camshaft/Rocker Arm Assembly
Piston Assembly
LH Crankcase Cover
RH Crankcase Cover, Magneto, and Associated Parts
RH Crankcase Internals
LH Crankcase Cover and Associated Parts
Crankcase Assembly
Transmission Case Assembly
Drive Wheel Clutch Assembly
Kick Start Gear Assembly
Transition Gear Assembly
Variator Assembly
Starter Clutch Assembly
CHASSIS
TORQUE SPECIFICATIONS
COMPONENT GUIDE
Front Wheel Assembly
Rear Wheel Assembly
Exhaust Assembly
Front Fork Assembly
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PREFACE______________________________________
This service manual serves as KEEWAY America’s promise of quality service and
technical support for its entire line of vehicles. This manual is intended to provide most
of the necessary information for the proper service and maintenance of all 50cc scooters.
KEEWAY 50cc scooters lie on the cutting edge of technology, offering such creature
comforts as:
Fully-automatic, belt-driven transmission
Forced air-cooling system
CDI ignition system
Electric start with security system/remote start capabilities
These 50cc scooters are intended to fit the needs of a wide array of potential riders. In
order to remain familiar with the proper service procedures, authorized technicians
should periodically review this manual.
Please understand that this service manual acts as a general guide for KEEWAY’s entire
line of 50cc, 2-stroke scooters. Model-specific information such as vehicle
specifications, wiring diagrams and technical/service bulletins will follow, keeping this
guide as complete and current as possible.
For any questions or concerns not addressed in this service manual or any succeeding
documents, please don’t hesitate to contact KEEWAY America directly.
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KEEWAY SERVICE GUIDELINES
1.
Use only genuine KEEWAY parts, and use proper lubricants where
specified.
2.
Use only the proper tools for the task at hand.
3.
Please be sure to replace all washers, seals, o-rings, cotter pins, etc.
4.
Please note that all fasteners are metric.
5.
When reassembling fasteners, please snug nuts and bolts in a circular
pattern, and torque to spec in a diagonal, star pattern (if applicable).
6.
Upon completion of assembly, double check fastener tension (torque)
and ensure free movement of parts.
7.
Parts and fasteners should be free of debris prior to measurement.
Upon assembly, use lubricant, or thread lock as needed.
8.
When metal parts are removed, and need to be stored for extended
periods, please apply a heavy coat of lubricant to minimize rust and debris
accumulation.
ELECTRICAL PRECAUTIONS
A loose or dangling cable is a tremendous hazard. Ensure fasteners are in place and
secure.
Never leave wire exposed, especially near any metal surface, including nuts and
bolts.
Only lay wire in straight, relaxed manner. Never stretch, twist, or sharply bend wire
or electrical connectors, or loss of conductivity will occur.
Keep wires away from heat sources and moving parts/rotating assemblies to avoid
electrical damage.
Inspect pigtails and connectors before connecting to wire to ensure a clean, firm
contact.
When making repairs to wires and connectors, please be sure to wrap the new joint
in heat-shrink tubing. This will reinforce the connection and protect it from the
elements.
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SAFETY GUIDELINES
WARNINGS:
Use only the appropriate, well-maintained tool for the task at hand.
Gasoline is a highly volatile chemical, and should be treated with care. Never handle
near open flame or heat source.
Keep floor clean and free of debris. Avoid fluid spills to minimize the risk of
accidents and equipment damage.
Exhaust fumes are hazardous to your health. Never operate engine in closed or
poorly ventilated areas.
BRAKE DUST CONTAINS ASBESTOS. Use of a dry brush or compressed air will
increase the risk of inhaling asbestos fibers, which carries a high risk of damage to
the respiratory system.
AVOID EYE AND PROLONGED SKIN CONTACT with brake cleaner. If this
occurs, immediately and thoroughly flush affected area with water and seek medical
assistance.
Only use DOT-approved brake fluid from a sealed container to ensure no moisture
absorption. Avoid fluid splash/overflow onto painted or rubber parts, as rapid
deterioration can occur.
BATTERIES CONTAIN ELECTROLYTE SOLUTION. Exercise caution and
wear protective clothing and eyewear. If accidental exposure occurs, immediately
and thoroughly flush affected area with water and seek medical assistance.
Please maintain sufficient communication with coworkers to maintain productivity
and minimize accident potential.
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SPECIALTY TOOLS REQUIRED
T01
T-Driver and socket set
(8, 10, 12, 13mm, and screwdriver bits
needed)
T02
Flywheel removal tool
T03
Valve spring compressor
T04
Spanner socket
T05
Cylinder compression tester
T06
Piston pin removal tool
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T07
13/16 Spark plug socket
(2 styles shown)
T08
Impact wrench
T9
Impact sockets
(17 & 18mm needed)
T10
Clutch clamp tool
T11
Torque wrench
(and appropriate sockets)
Recommend both lbs-ft and lbs-in
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GENERAL INFORMATION_________________________
TERMINOLOGY
The two absolute maximums of linear piston travel in the internal combustion engine are
referred to as TOP DEAD CENTER (TDC) and BOTTOM DEAD CENTER (BDC).
Note that TDC is at the point farthest from the rotation center of the crankshaft, and BDC is
the closest point.
The distance across the piston’s sleeve, or cylinder, is known as CYLINDER DIAMETER.
The STROKE is the distance the piston travels from TDC to BDC.
The cylinder’s DISPLACEMENT is achieved by calculating the cylinder’s volume (by
multiplying (½ DIAMETER) ²*π*STROKE), all in centimeters. (NOTE: total engine
displacement is achieved by multiplying this number by the total number of cylinders.) The
end measurement is cubic centimeters, or cc.
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THE 2-STROKE ENGINE CYCLE
The 2-stroke engine differs slightly from the 4-stroke, in that it combines its phases, or strokes.
Upon initial inspection, the most noticeable difference in overall 2-stroke architecture is the
location of the INTAKE PORT.
It provides a direct feed into the CRANKCASE, and then moves into the CYLINDER via the
TRANSFER PORT. The following better describes the process.
At the beginning of the engine’s first
revolution, the piston begins an upward
motion in the cylinder, which generates
pressure in the combustion chamber, and
creates a vacuum into the CRANKCASE.
NOTE: The piston skirt is blocking the
transfer and exhaust ports, but is allowing
the air/fuel mix to enter the crankcase via
the intake port.
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Now the piston is reaching TDC,
completely compressing the air/fuel mix in
the combustion chamber. NOTE: The
exhaust and transfer ports are still blocked
by the piston skirt; the intake port is still
open, but the crankcase has now filled to
capacity.
The spark plug now fires, igniting the
compressed mixture in the combustion
chamber.
Once the mix has been ignited, the
following explosion forces the piston
back down at a very high rate of speed.
This generates the power required to
perform the workload.
NOTE: All three ports are now closed.
As this downward motion occurs, the
air/fuel mixture in the crankcase is
compressed.
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This is the final, and perhaps most
complicated step in the 2-stroke process.
As the piston travels downward, the
EXHAUST PORT opens. This allows
the combusted gasses to exit the engine.
As the piston continues downward, the
TRANSFER PORT is now exposed.
This allows for the compressed mix in
the crankcase to expand and enter the
cylinder. NOTE: The intake port
remains closed. As the piston reaches
BDC, a new cycle begins.
This cycle of the 2-stroke engine translates into a fundamental rotational force inflicted
upon the crankshaft, known as TORQUE. This force is translated to the vehicle’s drive
wheel via a clutch assembly and drive belt. The metric unit of measurement for
TORQUE is equal to the unit of force multiplied by the length of the arm that inflicts it,
which is the Newton-meter (lb-ft standard).
In order to optimize the efficiency of this engine cycle and maximize TORQUE output,
the timing of ignition of the compressed air-fuel mixture is managed by the vehicle’s
CDI.
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VEHICLE INFORMATION
Engine Number
The engine number is stamped into the
rear of the crankcase, as shown in the
illustration.
Fuel
Be sure to only use unleaded fuel, 90 Octane or better.
Engine Oil
For KEEWAY’s oil injection system, high-quality engine oil is necessary. KEEWAY
America recommends full synthetic 2-stroke engine oil with the designation “suitable for
2-stroke oil injection systems”.
Gear Oil
High quality, all-purpose gear lube, SAE 90.
Break-in Duration
General guidelines are as follows:
• Limit break-in speed:
For the first 600 miles, do not exceed 4/5 throttle travel.
Beyond 600 miles, run at full throttle.
• Avoid prolonged idling and try to vary throttle position while riding during the
break-in period.
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GENERAL SPECIFICATIONS
Chassis
Front Shock Absorber Spring, Oil Damped
Rear Shock Absorber Spring, Oil Damped
Turn Angle 48° (to left/to right)
Brakes F/R Disk/Drum
Engine
Type 2-Stroke, Forced-Air-Cooling
Intake Piston-Reed Valve
Cylinder Single
Bore 40.0mm
Stroke 39.6mm
Displacement 49.8mL
Compression Ratio 6.9:1
Timing 15° BTDC @ 1500rpm
Carburetor Mechanical Slide
Start System Electric and Kick-start, Remote-Start Available
Lubrication System Oil-Injection/Pressure Lubrication
Transmission
Clutch System Dry, Fully Automatic Eccentric
Gearshift Step-less CVT
Gear Range 0.86~2.64
Electrical
Ignition Type CDI
Spark Plug BR8HSA
Generator A/C Magneto
Fuse 8A
FLUID CAPACITY
Fuel Tank 1.38 gal
Engine Oil Tank 1L
Gear Oil 3.4 oz.
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POWERTRAIN SPECIFICATIONS________________
FASTENER TORQUE
Self-tapping screws for fan cover assembly 1-3Nm (9-26 lbs-in)
Locknuts for fan cover assembly 10-12Nm (8-9lbs-ft)
Self-tapping screws for air cover 1-3 Nm (9-26 lbs-in)
Lock nut for air cover 10-12Nm (8-9lbs-ft)
Self-tapping screw and nut for cylinder head cover vent 1-3Nm (9-26lbs-in)
Locknut for cylinder head cover 10-12Nm (8-9lbs-ft)
Locknut for cylinder head 15-18Nm (11-13lbs-ft)
Spark plug 15-18Nm (11-13lbs-ft)
Intake port bolts 10-12Nm (8-9lbs-ft)
Exhaust port bolts 10-12Nm (8-9lbs-ft)
Carburetor joint locknuts 10-12Nm (8-9lbs-ft)
Cooling fan locknuts 10-12Nm (8-9lbs-ft)
Flywheel locknut 45-50Nm (33-36lbs-ft)
Stator coil locknuts 6-8Nm (4-6lbs-ft)
Magneto locknuts 10-12Nm (8-9lbs-ft)
Locknuts for RH crankcase cover 10-12Nm (8-9lbs-ft)
Locknut for oil pump 5-9Nm (3-7lbs-ft)
Locknut for driven clutch assembly 55-60Nm (40-44lbs-ft)
Locknut for driven clutch hub 35-38Nm (26-28lbs-ft)
RH crankcase locknut 10-12Nm (8-9lbs-ft)
Engine pivot bolt 55-60Nm (41-44lbs-ft)
LH crankcase cover locknut 10-12Nm (8-9lbs-ft)
Self-tapping screws for LH crankcase cover vent 3-6Nm (2-4lbs-ft)
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