Kawasaki FS481V Engine

General Technical Data

Kawasaki FS481V Engine Specifications

Engine Model .............. Kawasaki FS481V
Engine Type .............. 4-cycle vertical shaft V-twin OHV air-cooled gasoline engine
Number of Cylinders .............. 2
Cylinder Liners .............. Cast iron
Displacement, cc (cu.in) .............. 603 (36.8)
Cylinder Bore, mm (in) .............. 73.0 (2.87)
Piston Stroke, mm (in) .............. 72.0 (2.84)
Rated Engine Power, hp (kW) .............. 13.5 (10.0)
Rated Engine Speed, rpm .............. 3600
Maximum Torque, Nm (ft-lb) .............. 38.4 (28.3)
Torque Speed, rpm .............. 1800
Compression Ratio .............. 8.1:1
Lubrication System .............. Pressure feed by positive displacement pump
Cooling System .............. Forced-air
Oil Filter Type .............. Cartridge, full flow
Ignition System .............. Electronic
Air Cleaner Type .............. Dual stage element
Starting System .............. Electric or recoil starter
Electrical System Rating, Volts .............. 12

Fuel System

Fuel System .............. Carburetor
Carburetor Type .............. Internally vented with fuel shut-off solenoid
Fuel Pump Type .............. Diaphragm pulse pump
Governor Type .............. Flyweight all speed governor
Fuel Type .............. Gasoline (86 or higher)

Dimensions and Weight

Overall Length, mm (in) .............. 484 (19.1)
Overall Width, mm (in) .............. 434 (17.2)
Overall Height, mm (in) .............. 377 (14.9)
Net weight, kg (lbs) .............. 36.7 (81.0)

Kawasaki FS481V Maintenance Data

Cylinder Block and Valves

Cylinder Compression, kPa (psi) .............. 390 (57)
Cylinder Inside Diameter (Max), mm (in) .............. 73.10 (2.878)
Cylinder Head Warp, mm (in) .............. 0.05 (0.002)
Intake Valve Clearance, mm (in) .............. 0.10-0.15 (0.004-0.006)
Exhaust Valve Clearance, mm (in) .............. 0.10-0.15 (0.004-0.006)

Engine Oil and Filters

Engine Oil Type .............. SAE 10W-30, 10W-40, 5W-20
API Service Classifications .............. SJ or higher
Oil Capacity (w/o Filter), L (qts) .............. 1.5 (1.6)
Oil Capacity (with New Filter), L (qts) .............. 1.7 (1.8)
Oil Filter Part Number .............. 49065-7007
Air Filter Element Part Number .............. 11013-0752
Air Filter Pre-Cleaner Part Number .............. 11013-7041

Carburetor Adjustment

Pilot Screw Setting .............. 1-5/8±1/2 turns out
Low Idle Speed (Carburetor), rpm .............. 1450
Low Idle Speed (Governor), rpm .............. 1550
High Idle Speed, rpm .............. 3600

Ignition System

Spark Plug Type .............. NGK BPR4ES
Spark Plug Gap, mm (in) .............. 0.70-0.80 (0.0277-0.0316)
Coil Air Gap, mm (in) .............. 0.20-0.40 (0.0079-0.0158)
Spark Plug Torque .............. 22 Nm (16 ft-lb)

Service Intervals

Check Engine Oil Level .............. Every 10 hours
Service Air Filter Pre-Cleaner .............. Every 25 hours
Change Engine Oil .............. Every 100 hours
Clean and Adjust Spark Plug .............. Every 100 hours
Service Air Filter Element .............. Every 100 hours
Replace Engine Oil Filter .............. Every 200 hours
Replace Air Filter Element .............. Every 200 hours
Check Carburetor Adjustment .............. Every 300 hours
Check and Adjust Idle Speed .............. Every 300 hours
Check and Adjust Valve Clearance .............. Every 300 hours
Clean Combustion Chamber .............. Every 300 hours
Replace Spark Plug .............. Every 300 hours
Clean Fuel Line .............. Every 300 hours

Kawasaki FS481V Service Specifications

Cylinder Block

Cylinder Inside Diameter (Max), mm (in) .............. 73.10 (2.878)
Cylinder Bore Out Round, mm (in) .............. 0.056 (0.0022)
Connecting Rod Small End Inside Diameter, mm (in) .............. 16.05 (0.632)
Connecting Rod Bend, mm (in) .............. 0.15/100 (0.006/3.94)
Connecting Rod Big End Width, mm (in) .............. 19.00 (0.748)
Crankpin Width, mm (in) .............. 40.0 (1.57)
Connecting Rod Big End Inside Diameter, mm (in) .............. 38.04 (1.50)
Crankpin Outside Diameter, mm (in) .............. 37.94 (1.49)
Crankshaft Runout, mm (in) .............. 0.05 (0.002)
Crankshaft Journal Diameter (PTO), mm (in) .............. 37.90 (1.492)
Crankshaft Journal Diameter (Flywheel), mm (in) .............. 34.90 (1.374)
Crankshaft Bearing Inside Diameter, mm (in) .............. 38.10 (1.500)

Cylinder Head and Valves

Cylinder Head Warp, mm (in) .............. 0.05 (0.002)
Valve Clearance, mm (in) .............. 0.10-0.15 (0.0040-0.0059)
Valve Seat Angle, deg .............. 45
Valve Seat Width (Intake), mm (in) .............. 0.8-1.4 (0.03-0.06)
Valve Seat Width (Exhaust), mm (in) .............. 0.8-1.4 (0.031-0.055)
Valve Guide Inside Diameter, mm (in) .............. 6.00-6.012 (0.2362-0.2367)
Valve Head Thickness, mm (in) .............. 0.35 (0.014)
Valve Stem Runout, mm (in) .............. 0.05 (0.002)
Valve Stem Diameter (Intake), mm (in) .............. 5.95 (0.234)
Valve Stem Diameter (Exhaust), mm (in) .............. 5.93 (0.233)
Valve Guide Inside Diameter, mm (in) .............. 6.08 (0.239)
Valve Spring Free Length, mm (in) .............. 31.0 (1.22)
Rocker Arm Push Rod Runout, mm (in) .............. 0.5 (0.02)
Cam Lobe Height, mm (in) .............. 29.621 (1.166)

Piston and Piston Rings

Piston Outside Diameter, mm (in) .............. 72.79 (2.866)
Top Ring Groove Clearance, mm (in) .............. 0.12 (0.0047)
Second Ring Groove Clearance, mm (in) .............. 0.12 (0.0047)
Piston Ring Thickness, mm (in) .............. 1.1 (0.043)
Top Ring End Gap, mm (in) .............. 0.7 (0.028)
Second Ring End Gap, mm (in) .............. 0.9 (0.035)
Oil Ring End Gap, mm (in) .............. 1.05 (0.041)
Piston Pin Outside Diameter, mm (in) .............. 15.96 (0.628)
Piston Pin Hole Inside Diameter, mm (in) .............. 16.08 (0.633)

Tightening Torque Specs

Cylinder Head Bolts, Nm (ft-lb) .............. 27 (20)
Crankcase Cover Bolts, Nm (ft-lb) .............. 27 (20)
Flywheel Bolt, Nm (ft-lb) .............. 56 (41)
Valve Clearance Lock Screws, Nm (ft-lb) .............. 11 (8.2)
Connecting Rod Big End, Nm (ft-lb) .............. 9.8 (7.3)
Rocker Arm Bolts, Nm (ft-lb) .............. 14.7 (11)
Rocker Cover Mounting Bolts, Nm (ft-lb) .............. 5.9 (4.4)
Exhaust Pipe Flange Nuts, Nm (ft-lb) .............. 15 (11)
Spark Plugs, Nm (ft-lb) .............. 22 (16)
Governor Arm Clamp Nut, Nm (ft-lb) .............. 7.8 (5.8)
Carburetor Mounting Nut, Nm (ft-lb) .............. 5.9 (4.4)
Oil Drain Plug, Nm (ft-lb) .............. 6.9 (4.8)
Ignition Coil Bolts, Nm (ft-lb) .............. 5.9 (4.4)
Electric Starter Mounting Bolts, Nm (ft-lb) .............. 19.6 (14)
Intake Manifold Mounting Bolts, Nm (ft-lb) .............. 5.9 (4.4)