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Yamaha EH65 Engine

General Technical Data

Yamaha EH65 Engine Specifications

Engine Model ................ Yamaha EH65
Engine Type ................ 4-cycle V-twin cylinder OHV air-cooled gasoline engine
Number of Cylinders ................ Two
Displacement, cu.in (cc) ................ 39.9 (653)
Cylinder Bore, in (mm) ................ 3.15 (80.0)
Piston Stroke, in (mm) ................ 2.56 (65.0)
Rated Engine Power, hp (kW) ................ 17.0 (12.7)
Rated Engine Speed, rpm ................ 3600
Maximum Torque, Nm (ft-lbs) ................ 45.6 (33.4)
Torque Speed, rpm ................ 2500
Compression Ratio ................ 8.3:1
Valve Arrangement ................ Overhead valve
Cylinder Liner ................ Cast iron
PTO Shaft Rotation ................ Counterclockwise (from PTO shaft side)
Lubrication System ................ Full pressure by trochoid type pump
Air Cleaner Type ................ Double element
Cooling System ................ Forced air
Ignition System ................ Twin TCI
Starting System ................ Electric starter

Fuel System

Fuel System Type ................ Carburetor
Carburetor Type ................ Down draft, float
Fuel Pump Type ................ Diaphragm
Governor Type ................ Centrifugal, flyweight
Fuel Type ................ Gasoline (86 or higher)

Dimensions and Weight

Overall Length, in (mm) ................ 18.2 (463)
Overall Width, in (mm) ................ 19.4 (499)
Overall Height, in (mm) ................ 18.7 (476)
Dry Weight, lbs (kg) ................ 109 (49.5)

Yamaha EH65 Maintenance Data

Service Data

Cylinder Bore Inside Diameter (Max), in (mm) ................ 3.1542 (80.119)
Cylinder Head (Max. Out of Flatness), in (mm) ................ 0.004 (0.10)
Intake Valve Clearance, in (mm) ................ 0.003-0.005 (0.07-0.13)
Exhaust Valve Clearance, in (mm) ................ 0.003-0.005 (0.07-0.13)

Engine Oil and Filter

Engine Oil Type ................ Yamalube, SAE 20W, SAE 10W-30
API Service Classifications ................ SE or higher
Oil Capacity, qts (L) ................ 1.65 (1.55)
Air Filter Element Part Number ................ 263-32610-A1
Engine Oil Filter Part Number ................ 248-65801-20

Ignition System

Spark Plug Type ................ NGK BPR5ES
Spark Plug Gap, in (mm) ................ 0.028-0.032 (0.70-0.80)
Coil Air Gap, in (mm) ................ 0.012-0.020 (0.30-0.50)
Spark Plug Torque, Nm (ft-lbs) ................ 20 (14)

Service Intervals

Check Engine Oil Level ................ Every 10 hours
Service Air Filter Element ................ Every 50 hours
Check Battery Electrolyte Level ................ Every 50 hours
Clean and Adjust Spark Plug ................ Every 50 hours
Change Engine Oil ................ Every 100 hours
Replace Engine Oil Filter ................ Every 200 hours
Replace Air Filter Element ................ Every 200 hours
Clean Fuel Strainer ................ Every 200 hours
Replace Spark Plug ................ Every 300 hours
Check Carburetor Adjustment ................ Every 300 hours
Check and Adjust Idle Speed ................ Every 300 hours
Check and Adjust Valve Clearance ................ Every 500 hours
Check Fuel Lines ................ Every 500 hours

Yamaha EH65 Service Specifications

Cylinder Head And Valves

Cylinder Head Flatness, in (mm) ................ 0.002 (0.05)
Valve Seat Contact Width, in (mm) ................ 0.028-0.039 (0.7-1.0)
Valve Guide Inside Diameter, in (mm) ................ 0.2376-0.2383 (6.035-6.053)
Valve Stem Outside Diameter, in (mm) ................ 0.2350-0.2356 (5.970-5.985)
Clearance Between Valve Stem And Valve Guide, in (mm) ................ 0.00197-0.00327 (0.050-0.083)
Tappet Stem Outside Diameter, in (mm) ................ 0.3525-0.3535 (8.954-8.979)
Tappet Guide Inside Diameter, in (mm) ................ 0.3543-0.3549 (9.00-9.015)
Tappet Guide Clearance, in (mm) ................ 0.000827-0.002402 (0.021-0.061)
Valve Spring Free Length, in (mm) ................ 1.5551 (39.5)

Cylinder Block

Cylinder Inside Diameter, in (mm) ................ 3.1496-3.1504 (80.000-80.019)
Piston Skirt Diameter, in (mm) ................ 3.148-3.149 (79.968-79.988)
Piston Ring Groove Side Clearance (Top), in (mm) ................ 0.0002-0.0035 (0.05-0.09)
Piston Ring Groove Side Clearance (2nd), in (mm) ................ 0.0012-0.0028 (0.03-0.07)
Oil Ring Groove Side Clearance (Oil), in (mm) ................ 0.0022-0.0069 (0.057-0.175)
Piston Pin Hole, in (mm) ................ 0.8263-0.8269 (20.989-21.002)
Piston Pin Outside Diameter, in (mm) ................ 0.8264-0.8268 (20.991-21.000)
Clearance Between Piston And Cylinder, in (mm) ................ 0.0005-0.0020 (0.012-0.051)
Piston Ring End Gap (Top), in (mm) ................ 0.0079-0.0157 (0.2-0.4)
Piston Ring End Gap (2nd), in (mm) ................ 0.0079-0.0157 (0.2-0.4)
Piston Ring End Gap (Oil), in (mm) ................ 0.0079-0.0276 (0.2-0.7)
Connecting Rod Big End Inside Diameter, in (mm) ................ 1.5354-1.5361 (39.000-39.016)
Clearance Between Big End And Crankpin, in (mm) ................ 0.0012-0.0024 (0.030-0.060)
Connecting Rod Small End Inside Diameter, in (mm) ................ 0.8272-0.8277 (21.010-21.023)
Clearance Between Small End And Piston Pin, in (mm) ................ 0.0004-0.0013 (0.010-0.032)
Connecting Rod Big End Side Clearance, in (mm) ................ 0.0039-0.0127 (0.1-0.4)
Crankpin Outside Diameter, in (mm) ................ 1.5337-1.5343 (38.956-38.970)
Crankshaft Journal Diameter (Pto Side), in (mm) ................ 1.77102-1.77165 (44.984-45.000)
Crankshaft Journal Diameter (Flywheel Side), in (mm) ................ 1.77110-1.77154 (44.986-44.997)
Cam Height, in (mm) ................ 1.392-1.393 (35.35-35.37)
Camshaft Journal Outside Diameter, in (mm) ................ 0.7861-0.7866 (19.967-19.980)

Tightening Torques

Cylinder Head Bolts, Nm (ft-lb) ................ 41-49 (30.2-36.1)
Connecting Rod Cap Bolts, Nm (ft-lb) ................ 22-27 (16.3-19.8)
Flywheel Nut, Nm (ft-lb) ................ 100-120 (73.8-88.5)
Rocker Cover, Nm (ft-lb) ................ 6.8-8.8 (5.0-6.5)
Rocker Arm Lock Nut, Nm (ft-lb) ................ 6.8-8.8 (5.0-6.5)
Breather Cover, Nm (ft-lb) ................ 2.9-4.9 (2.2-3.6)
Carburetor Bolts, Nm (ft-lb) ................ 16.6-18.6 (12.3-13.7)
Intake Manifold Bolts, Nm (ft-lb) ................ 16.6-18.6 (12.3-13.7)
Main Bearing Cover Bolts, Nm (ft-lb) ................ 22.5-27.5 (16.5-20.2)
Oil Filter, Nm (ft-lb) ................ 9.9-14.7 (7.3-10.8)
Oil Pressure Switch, Nm (ft-lb) ................ 5.9-9.8 (4.3-7.2)
Oil Relief Plug, Nm (ft-lb) ................ 14.7-24.5 (10.8-18.0)
Charge Coil, Nm (ft-lb) ................ 2.9-3.9 (2.2-2.9)
Ignition Coil, Nm (ft-lb) ................ 6.8-8.8 (5.0-6.5)