Target Audience:
Entry-level scooter buyers and commuters seeking an economical 50cc two-wheeler
Also Useful For:
DIY owners and technicians servicing the SH50
Key Advantage:
Lightweight, simple two-stroke design with low maintenance costs and easy repair access
Competitors:
Honda Elite 50, Suzuki Verona
Engine:
Air-cooled 49cc two-stroke single with autolube oil injection
Transmission:
Automatic CVT
Weight:
Very light curb weight for easy handling
Engine:
Cylinder head, cylinder, piston, crankshaft, and reed valve service
Fuel System:
Carburetor disassembly, cleaning, and tuning; fuel tank and petcock
Oil Injection:
Autolube pump service, bleeding, and adjustment
Cooling:
Air-cooled shroud and fin cleaning procedures
Ignition:
CDI unit, ignition coil, spark plug, and flywheel magneto testing
Transmission:
CVT drive belt, variator, clutch shoe, and rear pulley service
Final Drive:
Gear unit oil change and inspection
Electrical:
Wiring diagrams, lighting, horn, switches, and battery
Chassis:
Frame, steering head, front fork, and handlebar service
Brakes:
Drum brake inspection, shoe replacement, and cable adjustment
Wheels & Tires:
Wheel removal, bearing replacement, tire service
Suspension:
Front fork seal and oil service, rear unit inspection
Body:
Body panel and seat removal and installation
Starter System:
Electric starter, kick starter, and starter clutch
Troubleshooting:
Symptom-based charts for starting, running, and electrical faults
Periodic Maintenance:
Service interval checks, lubrication, and adjustments
Specifications:
Torque values, clearances, and wear limits for all fasteners and parts
Special Tools:
Required tools listed for each procedure
Exploded Diagrams:
Detailed part views with identification
Torque Specs:
Step-by-step torque sequences included
File Format:
PDF (searchable, bookmarked, zoomable)
Compatibility:
Windows, macOS, Linux, iOS, and Android — any device with a PDF reader
Requirements:
A PDF reader application (e.g. Adobe Acrobat Reader, free)
Searchability:
Fully text searchable for fast lookup of any topic
Print Quality:
High-resolution digital pages, printable at full clarity
Binding Type:
N/A — digital download, no physical binding
Paper Type:
N/A — digital download, no physical paper
Primary Engine:
Single 49cc (49.2cc) air-cooled two-stroke single cylinder
Bore x Stroke:
40.0 mm x 39.2 mm
Compression Ratio:
Approximately 6.8:1
Lubrication:
Yamaha Autolube oil injection
Carburetor:
Slide-type carburetor
Ignition:
CDI electronic ignition
Starting:
Electric and kick start
Performance:
Approximately 4-5 hp, speed-restricted for the 50cc class
Fuel:
Regular unleaded gasoline
Crash Test Ratings:
N/A - mopeds/scooters of this class were not crash tested
Brakes:
Drum brakes front and rear
Lighting:
Headlight, taillight, and turn signals
Mirrors:
Left and right rearview mirrors standard
Initial Service:
Break-in check at 500 km (300 mi)
Periodic Service:
Every 1,500-3,000 km depending on severity of use
Spark Plug:
Inspect/replace per interval; typical gap 0.6-0.7 mm
Drive Belt:
Inspect at regular intervals, replace when worn
Gear Oil:
Change at intervals per manual schedule
Engine Oil (Autolube):
Yamaha 2-stroke injection oil or equivalent API TC
Gear Oil:
SAE 10W-30 or 10W-40 SE motor oil
Fuel Mix:
Not required - oil injection system meters oil automatically
Known Issues / Wear Items
Common Wear:
Drive belt, clutch shoes, spark plug, brake shoes
Two-Stroke Care:
Keep cooling fins clean; carbon buildup in exhaust possible
Fuel System:
Carburetor cleaning needed after storage
Manufacturer:
Yamaha Motor Company, founded 1955, Japan
Model Evolution:
The Razz SH50 was Yamaha's entry-level 50cc scooter sold in the US from 1987 through 2000, largely unchanged mechanically across the run
Production Location:
Japan
Successor:
Yamaha continued its 50cc scooter line with subsequent models