The Kawasaki FH641V is a 0.68 l (675 cc, 41.19 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.
The FH641V has V-twin 90° design with cast iron cylinder liners and overhead valves (OHV). The engine is equipped with twin-barrel, float type carburetor with fixed main jet; pulse type fuel pump and flywheel magneto transistor type ignition system. The Kawasaki FH641V uses a full pressure lubrication system with spin-on oil filter and dual element air cleaner.
The engine has BENDIX type electric starter and 12V-13A charging coil with a regulator.
A 75.2 mm (2.96 in) cylinder bore and 76 mm (2.99 in) piston stroke give the motor a total of 675 cc of displacement. Compression ratio rating is 8.1:1. The Kawasaki FH641V produced 21.4 PS (15.7 kW; 21.0 HP) at 3,600 rpm and 52.1 Nm (5.31 kg·m; 38.45 ft·lb) at 2,400 rpm of torque.
General information
| Engine Specifications | |
| Model | FH641V |
| Type | 4-stroke, OHV, V-twin 90° |
| Displacement | 675 cm 3 (41.2 cu-in) |
| Max. horsepower | 21.4 PS (15.7 KW; 21.0 HP) at 3,600 rpm |
| Max. torque (crank PTO) | 52.1 Nm (5.3 kg·m; 38.4 ft·lb) at 2,400 rpm |
| Carburetor | Twin barrel, float type |
| Cooling system | Air-cooling |
| Ignition system | Flywheel magneto transistor type |
| Lubricating system | Full pressure with spin-on oil filter |
| Starting system | Electric starter |
| Charging system | 12 Volt – 13A with regulator |
| Fuel used | Unleaded gasoline (octane number 86 or higher) |
| Fuel consumption | 245 g/HPh |
| Cooling system | Pressurized forced circulation type |
Dimensions and Weight
| Kawasaki FH641V | |
| Length, mm (in) | 458 (18.0) |
| Width, mm (in) | 430 (16.9) |
| Height, mm (in) | 461 (18.1) |
| Dry weight, kg (lb) | 40.0 (88.2) |
Tightening torque specs
| Tightening torque specs | Cylinder head | 28 Nm; 2.8 kg·m; 20.6 ft·lb |
| Connecting rod | 10 Nm; 1.0 kg·m; 7 ft·lb |
| Flywheel | 56 Nm; 5.7 kg·m; 41.3 ft·lb |
| Intake manifold | 6 Nm; 0.6 kg·m; 4.4 ft·lb |
| Valve clearance lock nut | 7 Nm; 0.7 kg·m; 5.1 ft·lb |
Maintenance data
| Engine | |
| Maximum speed | 3500 ± 100 rpm |
| Idle speed | 1500 ± 100 rpm |
| Cylinder compression | 3.9 kg/cm2 (56 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 (SF, SG, SH, or SJ ) |
| Recommended oil | SAE 10W-40, 10W-30, 5W-20 |
| Oil capacity (with filter changed) | 1.8 litre (1.9 US.qt.) |
| Ignition system | |
| Spark plug | NGK: BPR4ES |
| Spark plug gap | 0.75 mm (0.029 in) |
| Spark plug tightening torque | 22 Nm; 2.2 kg·m; 16.2 ft·lb |
Author:
I need help. I have to replace a Kawasaki V641. I need to know the diameter of the verical shaft coming down out of the bottom of the engine. I am having a hard time reading the spec sheets, as this kind of stuff is out of my expertise. Would you be able to help me with this?
Did you ever get this info? I’m searching for the same thing.