Specifications and Service Data


1) Engine and Performance
2) Dimensions
3) Chassis
4) Electrical wiring diagram
5) Ignition
6) Torque values
7) Wear limits
8) Bearing and seal sizes
Website sponsored by....

sponsor's logos

1) Engine and performance

Engine Air cooled 2-stroke twin
Bore and stroke 54mm x 54mm (2.1 x 2.1 in.)
Displacement 247cc (15.1 cu in.)
Compression ratio 7.3 : 1
Carburettors Mikuni VM 24 SH (x2)
Carburettor float level 0.98 inch (25.0mm)
Carburettor idle mixture screw Screw out approx 1.75 turns
Maximum power 29bhp @ 7500rpm
Maximum speed 100mph
Acceleration Standing 1/4 mile in 15.1s
Braking distance 39.4 foot @ 30mph
Maximum torque 20.3 ft-lb @ 7000rpm
Maximum rev limit 8000rpm
Gearbox 6-speed constant mesh
Overall top gear ratio 6.171 : 1
mph/revs in 6th 100mph/8800rpm
Clutch Wet, 12 plate

Back to top

2) Dimensions

Length 76.8 inch (1.95m)
Width 30.1 inch (0.765m)
Height 40.6inch (1.02m)
Wheelbase 50.4 inch (1.28m)
Ground clearance 6.5 inch (0.165m)
Dry weight 297lb (135kg)

Back to top

3) Chassis

Steering angle 45°
Caster 63°
Trail 3.3 inch
Turning radius 78.7 inch
Steering damper Friction plate
Front brake type Twin leading shoe drum
Rear Brake type Single leading shoe drum
Front suspension hydraulically damped telescopic fork
Fork leg oil capacity 200cc per leg
Rear suspension hydraulically damped swinging arm
Fuel tank capacity 3.1 gallon (3.7 US gal) 14 litre
Oil tank capacity 2.3qt.
Tyre sizes / pressures
- front
- back

2.75 x 18in / 22psi
3.00 x 18in / 26psi

Back to top

4) Electrical

Alternator 12V permanent magnet
single phase AC type
A.C. Output 2000rpm 17-33V
5000rpm 40-59V

Output 75-100W???
Battery 12V 5 Amp Hour
Main fuse 15 Amp
Headlamp 12v 35/25W
Tail/brake lamp 12V 5/21W
Neutral and parking lamps 12V 3.4W
Speedometer lamps 12V 3.4W
High beam indicator lamp 12V 1.5W
Turn signal indicator lamp 12V 1.5W
Wiring Diagram

Back to top

5) Ignition

Ignition timing 27° (3.63mm) before TDC
Spark plugs NGK B-77 HC
Spark plug gap 0.024 inch (0.6mm)
Contact breaker points gap 0.012-0.016 inch (0.3-0.4mm)
Condensor (capacitor) capacity 0.20-0.28 µFarad
Condensor insulation resistance Greater than 10 MegaOhm
Ignition coil resistance Between + and - terminals should be 1-2 Ohms
Ignition coil resistance Primary to secondary coil resistance is 5k to 11k Ohms

Back to top

6) Torque values

Cylinder head bolts 14 ft/lb
Engine pinion nut 31 ft/lb
Clutch sleeve nut 24 ft/lb
Final drive sprocket nut 36 ft/lb
Rotor bolt 14 ft/lb
Fork yoke bolts 58 ft/lb
Handlebar bracket bolts 11 ft/lb
Rear suspension unit nuts 18 ft/lb
Swing arm pivot nut 33 ft/lb
Front and rear wheel spindle 31 ft/lb

Back to top

7) Wear limits

Ring Gap 0.004 inch Wear limit max 0.04 inch
Clutch plate thickness 0.118 inch Minimum 0.110 inch
Clutch spring length 1.87 inch Minimum length 1.79 inch
Primary gear/primary pinion backlash Measure with solder squashed in gap - 0.006inch max
Connecting rod side to side motion (not end float) max 0.118 at top of rod
Gear fork/gear groove clearance Maximum value 0.032 inch

Back to top

8) Bearing and Seal sizes

Front wheel 6202 Z
Rear wheel 6303 Z
6203 Z
Sprocket casing 6205 Z
Gearbox output shaft 6304 NS-1 (KOYO) or
6304 1NX (NSK)
Clutch shaft bearing 6304 NS-1 (KOYO) or
6304 1NX (NSK)
Steering head bearings 48mm x 32mm
Rear sprocket oil seal 52mm x 30mm x 8mm
Front sprocket oil seal 52mm x 25mm x 7mm
Kickstart oil seal 30mm x 16mm x 8mm
Front fork seals 46mm x 34mm x 11mm

Back to top

N.B. The data above is true to the best of my Knowledge, but I can accept no liability for any mistakes.
Please send me any corrections or other information that you know of. Does anyone out there have copies of original service sheets?

If you are interested in Suzuki T20's and would like to add to this page, ask a question or just want to say hello, Then please send me an E-mail.
Version 3.01 October 2003. © Adrian Baker