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Kawasaki FH721V Engine

General Technical Data

Kawasaki FH721V Engine Specifications

Engine Model .......... Kawasaki FH721V
Engine Type .......... Forced Air-cooled, Vertical Shaft, OHV, 4-Stroke Gasoline Engine
Number of Cylinder .......... 2
Cylinder Layout .......... 90 V-Twin
Piston Displacement, cc (cu.in) .......... 675 (41.2)
Engine Bore, mm (in) .......... 75.2 (2.96)
Engine Stroke, mm (in) .......... 76.0 (2.99)
Engine Power, Hp (kW) .......... 25.3 (18.6)
Maximum Torque, Nm (ft-lb) .......... 56 (41.3)
Fast Idle Speed, rpm .......... 3600
Low Idle Speed, rpm .......... 1550
Compression Release .......... Automatic compression release
Direction of Rotation .......... Counterclockwise facing the PTO Shaft
Choke Control .......... Automatic (with Throttle Control)
Cooling System .......... Forced air cooling by fan
Air Cleaner .......... Dual stage element, dry type

Lubricating System

Lubricating System Type - Pressure feed by positive displacement pump
Oil Filter - Cartridge type full flow filter
Oil Pressuer Switch - ON-OFF switch
Engine oil capacity, L (qts) .......... 1.9 (2.0)

Fuel System

Fuel System Type .......... Carburetor
Carburetor Type .......... Float type, fixed main jet, two barrel
Fuel Pump .......... Diaphragm Type Pulse Pump
Governor .......... Flyweight all speed governor
Fuel Capacity, L (qt) .......... 11.0 (11.2)

Ignition System

Ignition System Type .......... Transistorized Flywheel Magneto
Charging Coil .......... 12V-13 amps with regulator
Spark Plug .......... NGK BPR4ES
Spark Plug Gap, mm (in) .......... 0.75 (0.029)
Spark Plug Torque, Nm .......... 22 (16.2)

Electrical System

Electrical System Rating, Volts .......... 12
Alternator Charging Capacity, Amp .......... 13
Electric Starter .......... 12V-0.6 kW
Recommended Battery .......... 12V-200CCA

Dimensions

Length, mm (in) .......... 458 (18.1)
Width, mm (in) .......... 430 (16.9)
Height, mm (in) .......... 381 (15.0)
Dry weight, kg (lbs) .......... 41.2 (91)

Kawasaki FH721V Maintenance Data

Fuel Type (min. octane) .......... 86 Octane Unleaded
Engine oil type .......... SAE 10W-40, 10W-30, 5W-20
Engine oil capacity, L (qts) .......... 1.9 (2.0)
Oil filter change interval .......... Every 150 hours
Oil change interval .......... Every 100 hours
Fuel filter change interval .......... Every 100 hours

Kawasaki FH721V Service Specifications

Cylinder Head and Valves

Cylinder head warp, mm (in) .......... 0.05 (0.002)
Valve clearance (Intake, Exhaust), mm (in) .......... 0.075-0.125 (0.003-0.005)
Valve seating surface angle (Intake, Exhaust), deg .......... 45
Valve seating surface width (Intake), mm (in) .......... 0.8-1.4 (0.03-0.06)
Valve seating surface width (Exhaust), mm (in) .......... 1.1-1.6 (0.04-0.06)
Valve guide inside diameter (Intake, Exhaust), mm (in) .......... 6.00-6.012 (0.2362-0.2367)
Valve head thickness (Intake, Exhaust), mm (in) .......... 0.35 (0.014)
Valve stem runout (Intake, Exhaust), mm (in) .......... 0.05 (0.002)
Valve stem diameter (Intake), mm (in) .......... 5.95 (0.0234)
Valve stem diameter (Exhaust), mm (in) .......... 5.93 (0.0233)
Valve guide inside diameter (Intake, Exhaust), mm (in) .......... 6.08 (0.239)
Valve spring free length (Intake, Exhaust), mm (in) .......... 31.0 (1.22)
Rocker arm push rod run out (Intake, Exhaust), mm (in) .......... 0.5 (0.02)

Cylinder and Pistons

Cylinder compression, kPa (psi) .......... 390 (57)
Cylinder inside diameter (Standard), mm (in) .......... 75.28 (2.964)
Cylinder inside diameter (0.50 Oversize), mm (in) .......... 75.78 (2.983)
Cylinder bore diameter (Standard), mm (in) .......... 75.18-75.20 (2.960-2.961)
Cylinder bore diameter (0.50 Oversize), mm (in) .......... 75.68-75.70 (2.979-2.980)
Cylinder bore out round, mm (in) .......... 0.056 (0.0022)
Piston diameter, mm (in) .......... 74.99 (2.952)
Piston top ring/groove clearance, mm (in) .......... 0.18 (0.007)
Piston second ring/groove clearance, mm (in) .......... 0.16 (0.006)
Piston ring thickness, mm (in) .......... 1.40 (0.055)
Piston top ring end gap, mm (in) .......... 0.65 (0.026)
Piston second ring end gap, mm (in) .......... 0.78 (0.031)
Piston 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)
Connecting rod small end inside diameter, mm (in) .......... 16.05 (0.632)
Cam lobe height, mm (in) .......... 29.621 (1.166)

Crankshaft and Connecting Rod

Connecting rod big end width, mm (in) .......... 19.90 (0.783)
Crankpin width, mm (in) .......... 43.1 (1.697)
Connecting rod big end inside diameter, mm (in) .......... 38.055 (1.498)
Crankpin outside diameter, mm (in) .......... 37.94 (1.494)
Crankshaft journal diameter, mm (in) .......... 39.896 (1.571)
Crankshaft journal bearing inside diameter, mm (in) .......... 40.15 (1.581)

Caburetor Specifications

Model - Nikki 621266
Throttle bore diameter, mm - 26 mm
Venturi diameter, mm - 21 mm
Main Jet - L: #136, R: #140
Pilot jet - L: #46, R: #44
Main air jet, mm - 1.7
Pilot air jet, mm - 1.1
Pilot air screw turns out (PS) - L: 2-1/4, R: 1-1/4

Lubricating System

Oil pressure, kPa (psi) .......... 241-310 (35-45)
Oil pressure switch, kPa (psi) .......... 98 (14.2)
Oil filter by-pass valve openning pressure, kPa (psi) .......... 78.5-117.5 (11.4-17.1)
Oil pump inner and outer rotor clearance, mm (in) .......... 0.2 (0.008)
Oil pump outer rotor outside diameter, mm (in) .......... 40.470 (1.5933)
Oil pump housing inside diameter, mm (in) .......... 40.801 (1.6063)
Oil pump housing depth, mm (in) .......... 10.230 (0.4028)
Oil pump shaft outside diameter, mm (in) .......... 10.923 (0.4300)
Oil pump shaft bearing inside diameter, mm (in) .......... 11.072 (0.4359)
Relief valve spring free length, mm (in) .......... 19.50 (0.77)

Tightening Torque Specs

Cylinder Head Bolts .......... 25 Nm (19 ft-lb)
Valve Clearance Lock Screws .......... 6.9 Nm (61 in-lb)
Connecting Rod Big End .......... 5.9 Nm (52 in-lb)
Rocker Arm Bolts .......... 28 Nm (20 ft-lb)
Rocker Cover Mounting Bolts .......... 5.9 Nm (52 in-lb)
Exhaust Pipe Flange Nuts .......... 15 Nm (11 ft-lb)
Spark Plugs .......... 22 Nm (16 ft-lb)
Drain Screw (Carburetor) .......... 1.3 Nm (11 in-lb)
Governor Arm Clamp Nut .......... 7.8 Nm (69 in-lb)
Intake Manifold Mounting Bolts .......... 5.9 Nm (52 in-lb)
Cleaner Body Mounting Screws .......... 3.4 Nm (30 in-lb)
Plug Bolt (Engine-shroud) .......... 5.9 Nm (52 in-lb)
Plug Screw (Engine-shroud) .......... 3.4 Nm (30 in-lb)
Choke Valve Screw .......... 0.7 Nm (6 in-lb)
Throttle Valve Screws .......... 1.0 Nm (9 in-lb)