The Kawasaki FS481V is a 0.6 l (603 cc, 36.8 cu-in) V-twin 90° air-cooled 4-stroke internal combustion small gasoline engine with vertical shaft, manufactured by Kawasaki Heavy Industries LTd., for general-purpose applications, such as zero-turn riders, lawn and garden tractors and wide-area walk-behind mowers.
The FS481V has 90 degrees V-twin design with vertical PTO shaft, overhead V-valves, cast iron cylinder liners, spherical combustion chamber, rotating grass screen and integrated clean out ports. The engine is equipped with electronic spark ignition system, internally vented carburetor with fuel shut-off solenoid. The motor uses a high-performance lubrication system and dual-element air filter.
The engine has an automatic compression release (ACR) system with bendix type starter. 13A or 20A charge coils, muffler, oil pressure switches, various oil drains are available as an option.
A 73.0 mm (2.87 in) cylinder bore and 72.0 mm (2.83 in) piston stroke give the motor a total of 603 cc, 36.8 cu-in of displacement. Compression ratio rating is 8.1:1. The Kawasaki FS481V produced 13.5 PS (9.9 kW; 13.2 HP) at 3,600 rpm or 14.7 PS (10.8 kW; 14.5 HP) at 3,600 rpm of maximum horsepower and 38.4 Nm (3.92 kg·m; 28.34 ft·lb) at 1,800 rpm or 42.0 Nm (4.28 kg·m; 31 ft·lb) at 1,800 rpm of torque.
General information
| Engine Specifications | |
| Model | FS481V |
| Type | 4-stroke, OHV, V-twin 90° |
| Displacement | 603 cm 3 (36.8 cu-in) |
| Max. horsepower |
13.5 PS (9.9 KW; 13.2 HP) at 3,600 rpm 14.7 PS (10.8 KW; 14.5 HP) at 3,600 rpm |
| Max. torque (crank PTO) |
38.4 Nm (3.92 kg·m; 28.34 ft·lb) at 1,800 rpm 42.0 Nm (4.28 kg·m; 31 ft·lb) at 1,800 rpm |
| Carburetor | Internally vented with fuel shut-off solenoid |
| Cooling system | Air-cooling |
| Ignition system | Electronic spark ignition |
| Lubricating system | Full pressure with spin-on oil filter |
| Starting system | Bendix type starter |
| Charging system | 13A or 20A charge coil (option) |
| Fuel used | Unleaded gasoline (octane number 86 or higher) |
| Fuel consumption | – |
| Cooling system | Pressurized forced circulation type |
Dimensions and Weight
| Kawasaki FS481V | |
| Length, mm (in) | 484 (19.1) |
| Width, mm (in) | 434 (17.1) |
| Height, mm (in) | 377 (14.8) |
| Dry weight, kg (lb) | 36.7 (80.9) |
Tightening torque specs
| Tightening torque specs | Cylinder head | 27.5 Nm; 2.75 kg·m; 20.3 ft·lb |
| Connecting rod | 10 Nm; 1.0 kg·m; 7.4 ft·lb |
| Flywheel | 56 Nm; 5.7 kg·m; 41.3 ft·lb |
| Crankcase cover | 27.5 Nm; 2.75 kg·m; 20.3 ft·lb |
| Intake manifold | 9 Nm; 0.9 kg·m; 6.6 ft·lb |
| Valve clearance lock nut | 11 Nm; 1.1 kg·m; 8.1 ft·lb |
Maintenance data
| Engine | |
| Maximum speed | 3500 ± 100 rpm |
| Idle speed | 1500 ± 100 rpm |
| Cylinder compression | 4.5 kg/cm2 (64 psi) at 500 rpm |
| Valve clearance | |
| Intake valve | 0.10-0.15 mm (0.004-0.006 in) |
| Exhaust valve | 0.10-0.15 mm (0.004-0.006 in) |
| Oil system | |
| Oil type | 4-stroke or an equivalent (SJ or higher class) |
| Recommended oil | SAE 10W-40, 10W-30 |
| Oil capacity (with filter changed) |
With oil filter: 1.7 litre Without oil filter: 1.5 litre |
| Ignition system | |
| Spark plug | NGK: BPR4ES |
| Spark plug gap | 0.7-0.8 mm (0.027-0.031 in) |
| Ignition coil air gap | 0.2-0.4 mm (0.008-0.011 in) |
| Spark plug tightening torque | 22 Nm; 2.2 kg·m; 16.2 ft·lb |
Author:
Your specs all seem to be correct. I used them to rebuild a 481. Started right up first pull. Retorqued head bolts after it cooled down.