Target User:
Owners, hobbyists, and independent mechanics who wish to perform maintenance and repairs on their Tomos Automatic A3 moped.
Value Proposition:
Provides essential technical information crucial for maintaining the operational integrity and longevity of a classic 1988 Tomos Automatic A3 moped, saving on dealership service costs.
Utility:
A vital resource for hands-on maintenance and repair, empowering users to keep their vintage moped in prime condition.
Engine Mechanical:
Complete overhaul and component-level repair of the Tomos A3 engine, including cylinder head, piston, connecting rod, crankshaft, bearings, and seals.
Fuel System:
Carburetor (likely Dell'Orto SHA or similar), fuel tank, fuel lines, fuel filter inspection and maintenance.
Ignition System:
Points ignition system (if applicable to A3 for '88), coil, spark plug, timing adjustments.
Cooling System:
Air cooling system, fin inspection and cleaning.
Transmission:
Automatic centrifugal clutch system, variator system (if equipped), drive belt inspection and replacement, primary drive gear inspection.
Brakes:
Front and rear drum brake system, brake shoe replacement, cable adjustment, linkage maintenance.
Electrical System:
Lighting system (headlight, taillight, indicators), wiring diagrams, horn, basic electrical component testing.
Chassis And Suspension:
Frame inspection, front fork (telescopic), rear suspension (swingarm, shock absorbers), wheel bearings, steering head bearings.
Bodywork:
Fenders, fuel tank, seat, side covers, and basic body panel removal/installation.
Routine Maintenance:
Oil change, spark plug replacement, air filter cleaning/replacement, chain lubrication (if applicable), general lubrication points.
Engine Rebuild:
Step-by-step instructions for engine disassembly, inspection, repair, and reassembly, including torque specifications.
Troubleshooting:
Common problems and diagnostic procedures for starting issues, poor running, braking problems, and electrical faults.
Carburetor Adjustment:
Detailed steps for cleaning, adjusting, and rebuilding the carburetor for optimal performance.
Brake Adjustment:
Procedure for adjusting brake cable tension and ensuring proper brake engagement.
Clutch Adjustment:
Inspection and potential adjustment of the automatic clutch mechanism and variator belt.
Wiring Diagrams:
Schematic diagrams for the electrical system to aid in diagnosis and repair.
Diagnostic Capabilities:
Covers basic to intermediate diagnostics, focusing on common mechanical and electrical issues encountered in this era of moped.
Repair Scope:
Comprehensive repair procedures, from simple adjustments to complete engine overhauls and component replacements.
Part Identification:
Likely includes exploded views of components to aid in identification and reassembly.
Engine Type:
Air-cooled, two-stroke, single-cylinder
Displacement:
Approximately 38cc to 49cc (depending on specific A3 variant, commonly 38cc for early models or 49cc if it's an A3M with a different engine).
Bore X Stroke:
Typically around 38mm x 33mm for the 38cc variant or 39mm x 41mm for the 49cc variant.
Power Output:
Around 2-3 horsepower at 5000-6000 RPM (estimate based on era and displacement).
Torque Output:
Low torque output, typical for small displacement two-strokes.
Carburetor Model:
Likely Dell'Orto SHA 14/12 or similar small-bore carburetor.
Fuel Type:
Unleaded gasoline mixed with two-stroke oil (e.g., 50:1 ratio specified by Tomos).
Ignition Type:
Contact breaker (points) ignition with internal flywheel magneto.
Piston Rings:
Single or dual piston rings depending on exact engine variant.
Bearings:
Crankshaft main bearings (e.g., 6202 type), small end needle roller bearing.
Wheelbase:
Approx. 1150-1200 mm (typical for this class of moped).
Seat Height:
Approx. 750-800 mm.
Dry Weight:
Approx. 50-60 kg.
Front Tire Size:
Typically 2.25-16 or 2.50-16.
Rear Tire Size:
Typically 2.25-16 or 2.50-16.
Wheel Type:
Spoked wheels with steel rims.
Bolt Pattern:
Not applicable for traditional spoke wheels, but hub mounting specifications would be detailed.
Oil Change:
Every 500-1000 km or annually (specified in manual).
Spark Plug Replacement:
Every 2000-3000 km or as needed based on condition.
Air Filter Cleaning:
Every 500 km, with replacement as needed.
Clutch And Variator Inspection:
Annually or every 1000-2000 km for belt wear and clutch engagement check.
Two Stroke Oil:
High-quality API TC or JASO FD rated two-stroke engine oil, mixed at a ratio of 50:1 (gasoline:oil) as per Tomos recommendations. Manual will specify exact grade.
Gear Oil:
If applicable to a specific A3 variant's gearbox, typically SAE 80W or SAE 90 gear oil. Manual will specify capacity and type.
Carburetor Fouling:
Common issue due to two-stroke oil and fuel deposits; requires regular cleaning and adjustment.
Ignition Points Wear:
Contact points can wear, requiring adjustment or replacement to maintain proper timing.
Clutch Slippage:
Can occur due to worn clutch shoes, springs, or belt slippage, often requiring inspection and replacement of components.
Required Tools:
Standard metric wrenches and sockets, screwdrivers, feeler gauges, torque wrench (for engine rebuild), specialized pullers (e.g., flywheel puller, clutch puller) might be needed and are likely detailed in the manual.
