Kawasaki FH381V Engine

General Technical Data

Kawasaki FH381V Engine Specifications

Engine Model .............. Kawasaki FH381V
Engine Type .............. 4-cycle vertical shaft OHV air cooled gasoline engine
Number of Cylinders .............. 2
Cylinder Layout .............. 90 deg, V-Twin
Displacement, L (cu in) .............. 0.431 (26.3)
Cylinder Bore, mm (in) .............. 65.0 (2.56)
Piston Stroke, mm (in) .............. 65.0 (2.56)
Rated Engine Power, hp (kW) .............. 13.0 (9.7)
Rated Engine Speed, rpm .............. 3600
Maximum Torque, Nm (ft-lb) .............. 27.5 (20.3)
Torque Speed, rpm .............. 2400
Compression Ratio .............. 8.5:1
Direction of Rotation .............. Counterclockwise (PTO-shaft)
Lubrication System .............. Full pressure
Oil Filter Type .............. Spin-on
Air Cleaner Type .............. Dual stage element
Cooling System .............. Forced air cooled
Starting System .............. Bendix type electric starter
Ignition System .............. Flywheel magneto transistor type
Electrical System Rating, Volts .............. 12

Fuel System

Fuel System .............. Carburetor
Carburetor Type .............. Float with fixed main jet
Fuel Pump Type .............. Pulse
Governor Type .............. Mechanical
Fuel Type .............. Gasoline (86 or higher)

Dimensions and Weight

Overall Length, mm (in) .............. 420 (16.5)
Overall Width, mm (in) .............. 355 (14.0)
Overall Height, mm (in) .............. 435 (17.1)
Net weight, kg (lbs) .............. 29.8 (65.7)

Kawasaki FH381V Maintenance Data

Cylinder Block and Valves

Cylinder Inside Diameter (Max), mm (in) .............. 65.10 (2.563)
Cylinder Compression, kPa (psi) .............. 390 (57)
Cylinder Head Warp, mm (in) .............. 0.03 (0.001)
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 .............. SF, SG, SH or SJ
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 .............. 49065-7010
Air Filter Element Part Number .............. 11013-7031
Air Filter Pre-Cleaner Part Number .............. 11013-7025

Ignition System

Spark Plug Type .............. NGK BPMR6A or Champion RCJ8Y
Spark Plug Gap, mm (in) .............. 0.75 (0.0296)
Coil Air Gap, mm (in) .............. 0.20-0.40 (0.0079-0.0158)
Spark Plug Torque, Nm (ft-lb) .............. 22 (16.3)

Carburetor Adjustments

Carburetor Model .............. Walbro LMF-2
Throttle Bore Diameter, mm (in) .............. 24.0 (0.95)
Venturi Diameter, mm (in) .............. 14.0 (0.55)
Main Jet .............. #78
Pilot Jet .............. #40
Float level .............. Float parallel to carburetor body
Pilot Screw Setting .............. 1-1/4 turn out
Low Idle Speed, rpm .............. 1550
High Idle Speed, rpm .............. 3600

Service Intervals

Check Engine Oil Level .............. Every 10 hours
Service Air Filter Pre-Cleaner .............. Every 25 hours
Service Air Filter Element .............. Every 50 hours
Change Engine Oil .............. Every 100 hours
Clean and Adjust Spark Plug .............. 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 FH381V Service Specifications

Cylinder Block

Cylinder Inside Diameter (Max), mm (in) .............. 65.10 (2.563)
Cylinder Bore Out Round, mm (in) .............. 0.056 (0.0022)
Cylinder Bore Diameter (Std), mm (in) .............. 65.00-64.98 (2.559-2.558)
Crankpin Width, mm (in) .............. 39.50 (1.56)
Crankpin Outside Diameter, mm (in) .............. 32.94 (1.297)
Crankshaft Journal Diameter (PTO), mm (in) .............. 34.90 (1.374)
Crankshaft Journal Diameter (Flywheel), mm (in) .............. 34.94 (1.376)
Crankshaft Journal Bearing Inside Diameter, mm (in) .............. 35.15 (1.384)
Connecting Rod Bend, mm (in) .............. 0.15/100 (0.006/3.94)
Connecting Rod Big End Width, mm (in) .............. 18.80 (0.74)
Connecting Rod Big End Inside Diameter, mm (in) .............. 33.055 (1.301)
Connecting Rod Small End Inside Diameter, mm (in) .............. 16.06 (0.632)
Camshaft Journal Diameter, mm (in) .............. 15.985 (0.6293)
Camshaft Bearing Inside Diameter, mm (in) .............. 16.136 (0.6352)

Cylinder Head and Valves

Cylinder Head Warp, mm (in) .............. 0.03 (0.001)
Valve Head Thickness, mm (in) .............. 0.35 (0.014)
Valve Stem Bend, 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, mm (in) .............. 6.08 (0.239)
Valve Spring Free Length, mm (in) .............. 31.5 (1.24)
Valve Clearance, mm (in) .............. 0.10-0.15 (0.004-0.006)
Valve Seating Surface Angle, degrees .............. 45
Valve Seating Surface Width, mm (in) .............. 0.6-0.9 (0.024-0.035)
Valves Guide Inside Diameter, mm (in) .............. 6.00-6.012 (0.2362-0.2367)
Rocker Arm Push Rod Rounout .............. 0.5 (0.02)
Rocker Arm Push Rod Runout, mm (in) .............. 0.5 (0.02)
Rocker Arm Collar Outside Diameter, mm (in) .............. 10.914 (0.4297)
Rocker Arm Bearing Inside Diameter, mm (in) .............. 11.132 (0.4382)
Cam Lobe Height, mm (in) .............. 29.131 (1.1469)

Piston and Piston Rings

Piston Diameter, mm (in) .............. 64.79 (2.551)
Piston Pin Outside Diameter, mm (in) .............. 15.96 (0.628)
Piston Pin Hole Inside Diameter, mm (in) .............. 16.08 (0.633)
Top Ring Groove Clearance, mm (in) .............. 0.18 (0.007)
Second Ring Groove Clearance, mm (in) .............. 0.18 (0.007)
Top Ring Width, mm (in) .............. 1.40 (0.055)
Second Ring Width, mm (in) .............. 1.40 (0.055)
Top Ring End Gap, mm (in) .............. 0.75 (0.029)
Second Ring End Gap, mm (in) .............. 0.75 (0.029)
Oil Ring End Gap, mm (in) .............. 1.05 (0.041)

Tightening Torque Specs

Cylinder Head, Nm (ft-lb) .............. 25 (18.5)
Connecting Rod, Nm (ft-lb) .............. 6 (4.5)
Flywheel, Nm (ft-lb) .............. 56 (41.3)
Crankcase Cover, Nm (ft-lb) .............. 25 (18.5)
Intake Manifold, Nm (ft-lb) .............. 7 (5.2)
Valve Clearance Lock Nut, Nm (ft-lb) .............. 7 (5.2)
Carburetor Float Chamber, Nm (ft-lb) .............. 4.5 (3.3)
Governor Arm Clamp, Nm (ft-lb) .............. 7.8 (5.8)
Spark Plug, Nm (ft-lb) .............. 22 (16.3)
Rocker Arm, Nm (ft-lb) .............. 28 (20.8)
Rocker Cover, Nm (ft-lb) .............. 5.9 (4.4)
Exhaust Pipe Flange, Nm (ft-lb) .............. 15 (11.1)