1977 ATC90 Specifications

General Specs
ManufacturerHonda
Year1977
ModelATC90
Model CodeATC90
Product Code942
Frame VIN LocationStamped into left side of frame neck
Engine Serial LocationStamped on bottom of left crankcase cover
Frame Starting NumberATC90-1600001
Engine Starting NumberATC90E-1600001
Owner Manual3194205
Service Manual6291806
Chassis
Length1600 mm (63 in)
Width970 mm (38.2 in)
Height890 mm (35 in)
Seat Height635 mm (25 in)
Wheelbase1015 mm (40 in)
Dry Weight103.5 kg (228.2 lb)
Caster Angle21°
Trail55 mm (2.17 in)
Tire & Rim
Front Tire Size22x11-8
Rear Tire Size22x11-8
Engine
Engine TypeOHC single cylinder 4 stroke air cooled
Cylinder ArrangementSingle cylinder inclined 75 degrees from vertical
Valve TrainOverhead camshaft - chain drive
Displacement89.5 cc (5.5 ci)
Bore50 mm (2 in)
Stroke45.6 mm (1.8 in)
Compression Ratio8.2:1
Cylinder Compression1059-1294 kPa (154-188 psi)
Horsepower5 PS (4.9 hp)
Starter TypeRecoil
Oil Capacity - Total0.95 L (1 US qt; 0.8 Imp qt)
Drive Train & Transmission
Clutch TypeAutomatic wet multiplate centrifugal
Transmission Type4 speed constant mesh dual range
Primary Reduction3.722
First Gear2.538
Second Gear1.611
Third Gear1.190
Fourth Gear0.958
Final Reduction3.267
DrivelineChain
Carburetor
BrandKeihin
Identification MarkU9B
TypePiston valve
Main Jet#65
Pilot Jet/Slow Jet#35
Jet Needle Clip Position3rd groove
Pilot Screw Adjustment1 Turn out
Float Level20 mm (0.8 in)
Engine Idle1300 RPM
Fuel Tank Capacity6 L (1.6 US gal; 1.3 Imp gal)
Fuel Tank Reserve1 L (0.3 US gal; 0.2 Imp gal)
Ignition
Ignition TypePoints
Spark PlugD-8HS (NGK)
X24FS (Denso)
Spark Plug Gap Max0.6-0.7 mm (0.024-0.028 in)
Points Gap Max0.3-0.4 mm (0.012-0.016 in)
Condenser Capacity0.25 μF
Initial Ignition Timing13.0° BTDC
Full Advance Ignition Timing25.0° BTDC
Electrical
Voltage6 V
Power TypeAC
Brakes
Front Brake TypeN/A
Rear Brake TypeDrum
Suspension
Front SuspensionRigid
Rear SuspensionRigid

Information on this page is provided in good faith that it is accurate, but in no way is the data guanteed to be accurate. If there are any mistakes, please contact me.