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John Deere 318 Engine

John Deere 318 Engine Specifications

Engine Model ............. Onan B43G (1983-1987) and Onan P218 (1987-1992)
Engine Type ............. Gasoline, 2-cylinder 4-valve
Number of cylinders ............. Two
Bore, mm (in.) ............. 82.6 (3.25)
Stroke (B43G), mm (in.) ............. 66.0 (2.62)
Stroke (P218), mm (in.) ............. 73.0 (2.88)
Total displacement (B43G), cm3 (cu. in.) ............. 709 (43.3)
Total displacement (P218), cm3 (cu. in.) ............. 782 (47.7)
Gross power, kw (hp) ............. 13.4 (18.0)
Maximum speed, rpm ............. 3500
Idle speed, rpm ............. 1350
Crankshaft Alignment ............. Horizontal
Cylinder Material ............. Aluminum
Compression ratio (B43G) ............. 6.5:1
Compression ratio (P218) ............. 7.0:1
Carburetor Model ............. Nikki, Marvel Schebler or Walbro
Fuel Pump Location ............. Engine
Fuel Pump Type ............. Pulse
Fuel Delivery ............. Fixed or Adjustable Jet Carburetor
Lubricating System Type ............. Full Pressure with filter
Oil filter ............. Replaceable
Ignition ............. Electronic
Type of Starter ............. 12 Volts, Solenoid
Charging System ............. 20 amp Stator
Battery Type ............. BCI Group 22F
Battery Voltage ............. 12V

John Deere 318 Engine Maintenance Data

Valve Adjustment

Intake Valve Clearance (Cold), in (mm) ............. 0.005 (0.13)
Exhaust Valve Clearance (Cold), in (mm) ............. 0.013 (0.33)
Intake/Exhaust Valve Seat Width, in (mm) ............. 0.031-0.047 (0.787-1.194)
Intake Valve Stem Diameter (B43G), in (mm) ............. 0.3425-0.3430 (8.70-8.71)
Exhaust Valve Stem Diameter (B43G), in (mm) ............. 0.3410-0.3415 (8.661-8.674)
Intake Valve Stem Diameter (P218), in (mm) ............. 0.2795 (7.099) - 0.2800 (7.112)
Exhaust Valve Stem Diameter (P218), in (mm) ............. 0.2780 (7.061) - 0.2785 (7.074)

Engine Oil and Filters

Oil classification (API) ............. SF, SF/CC, or SF
Engine oil type ............. SAE 20W-50, 5W-30
Engine oil capacity, L (qts) ............. 1.4 (1.5)
Oil Filter Part Number ............. AM101207
Air Filter Part Number ............. AM106953

Carburetor Adjustment (B43G)

Carburetor Model ............. Nikki
Main Fuel ............. 1-1/4 to 1-1/2 turns
Idle Fuel ............. 3/4 turns
Low Idle Speed, rpm ............. 1000±50

Carburetor Model ............. Marvel Schebler
Main Fuel ............. 1-1/4 turns
Idle Fuel ............. 1 turn
Low Idle Speed, rpm ............. 1200±50

Carburetor Model ............. Walbro
Main Fuel ............. 1-1/2 turns
Idle Fuel ............. 1-1/8 turns
Low Idle Speed, rpm ............. 1000±50

Carburetor Adjustment (P218)

1. Carburetor have a fixed main jet.
2. Carburetor has a limited adjustment range between stops of ±1/8 turn.
3. If replacing idle mixture screw, turn in until lightly seated, then turn screw back out 1-1/4 turns.
4. Replace limiter cap with the plastic stop approximately centered.

Ignition System

Spark Plugs ............. NGK BPR5EFS / Champion RS14YC
Spark Plug Gap, in (mm) ............. 0.025 (0.64)
Breaker Point Gap, in (mm) ............. 0.016 (0.41)
Ignition Timing (B43G), deg ............. 16 BTC
Ignition Timing (P218), deg ............. 20 BTC

John Deere 318 Engine Service Specifications

Cylinder Block

Cylinder Bore Honed Diameter, in (mm) ............. 3.2490-3.2500 (82.53-82.55)
Main Bearing Inside Diameter (Without bearing), in (mm) ............. 2.187-2.188 (55.55-55.58)
Main Bearing inside Diameter (Installed), in (mm) ............. 2.0015-2.004 (50.84-50.90)
Crankshaft Main Bearing Journal Diameter, in (mm) ............. 1.9992-2.0000 (50.78-50.80)
Crankshaft Main Bearing Clearance (B43G), in (mm) ............. 0.0025-0.0038 (0.064-0.097)
Crankshaft Main Bearing Clearance (P218), in (mm) ............. 0.0024-0.0042 (0.061-0.107)
Connecting Rod Journal Diameter, in (mm) ............. 1.6252-1.6260 (41.28-41.30)
Crankshaft End Play, in (mm) ............. 0.006-0.012 (0.15-0.30)
Connecting Rod Side Clearance, in (mm) ............. 0.0020-0.0160 (0.051-0.406)
Piston Pin Bushing Bore (Finished bore), in (mm) ............. 0.6879-0.6882 (17.47-17.48)
Bearing to Crankshaft Clearance (Aluminum Rod), in (mm) ............. 0.0020-0.0033 (0.051-0.084)
Camshaft Bearing Journal Diameter, in (mm) ............. 1.3740-1.3745 (34.90-34.91)
Camshaft Bearing Clearance, in (mm) ............. 0.0015-0.0030 (0.038-0.076)
Camshaft End Play (B43G), in (mm) ............. 0.0030 (0.076)
Camshaft End Play (P218), in (mm) ............. 0.0110-0.0480 (0.279-1.219)

Piston and Piston Rings

Piston Clearance in Cylinder, in (mm) ............. 0.0033-0.0053 (0.084-0.135)
Piston Pin Bore, in (mm) ............. 0.68774-0.68814 (17.48-17.47)
Top 1 Compression Ring Groove Width, in (mm) ............. 0.080-0.081 (2.032-2.057)
Top 2 Compression Ring Groove Width, in (mm) ............. 0.080-0.081 (2.032-2.057)
Oil Control Ring Groove Width, in (mm) ............. 0.188-0.189 (4.775-4.801)
Piston Pin Clearance in Piston, in (mm) ............. 0.00004-0.00064 (0.001-0.016)
Piston Pin Clearance in Connecting Rod, in (mm) ............. 0.0002-0.0007 (0.005-0.018)
Piston Pin Diameter, in (mm) ............. 0.6875-0.6877 (17.46-17.47)
Top Ring Groove Clearance, in (mm) ............. 0.003-0.008 (0.076-0.203)
Ring End Gap in Cylinder Clearance, in (mm) ............. 0.010-0.020 (0.254-0.508)

Valves (Onan B43G)

Intake Valve Stem Diameter, in (mm) ............. 0.3425-0.3430 (8.70-8.71)
Exhaust Valve Stem Diameter, in (mm) ............. 0.3410-0.3415 (8.661-8.674)
Intake Valve Clearance (Stem to Guide), in (mm) ............. 0.0010-0.0025 (0.025-0.064)
Exhaust Valve Clearance (Stem to Guide), in (mm) ............. 0.0025-0.040 (0.064-0.102)
Intake/Exhaust Valve Face Angle, degrees ............. 44
Intake Valve Seat Cylinder Bore Diameter, in (mm) ............. 1.4395-1.4405 (36.56-36.59)
Exhaust Valve Seat Cylinder Head Bore Diameter, in (mm) ............. 1.189-1.190 (30.20-30.23)
Intake Valve Seat Outside Diameter, in (mm) ............. 1.470-1.471 (37.34-37.36)
Exhaust Valve Seat Outside Diameter, in (mm) ............. 1.192-1.193 (30.28-30.30)
Intake/Exhaust Valve Seat Width, in (mm) ............. 0.031-0.047 (0.787-1.194)
Intake/Exhaust Valve Seat Angle, degrees ............. 45
Valve Guide Inside Diameter, in (mm) ............. 0.344-0.345 (8.74-8.76)
Valve Spring Free Length, in (mm) ............. 1.662 (42.21)
Valve Open, in (mm) ............. 1.125 (28.58)
Valve Closed , in (mm) ............. 1.375 (34.93)

Valves (Onan P218)

Intake Valve Stem Diameter, in (mm) ............. 0.2795 (7.099) - 0.2800 (7.112)
Exhaust Valve Stem Diameter, in (mm) ............. 0.2780 (7.061) - 0.2785 (7.074)
Intake Valve Clearance (Stem to Guide), in (mm) ............. 0.0010 (0.025) - 0.0025 (0.064)
Exhaust Valve Clearance (Stem to Guide), in (mm) ............. 0.0020 (0.051) - 0.035 (0.089)
Intake/Exhaust Valve Face Angle, degrees ............. 44
Intake Valve Seat Cylinder Bore Diameter, in (mm) ............. 1.4395 (36.56) - 1.4405 (36.59)
Exhaust Valve Seat Cylinder Head Bore Diameter, in (mm) ............. 1.189 (30.20) - 1.190 (30.23)
Intake Valve Seat Outside Diameter, in (mm) ............. 1.470 (37.34) - 1.471 (37.36)
Exhaust Valve Seat Outside Diameter, in (mm) ............. 1.192 (30.28) - 1.193 (30.30)
Intake/Exhaust Valve Seat Width, in (mm) ............. 0.031 (0.787) - 0.047 (1.194)
Intake/Exhaust Valve Seat Angle, degrees ............. 45
Intake Valve Guide Inside Diameter, in (mm) ............. 0.2810 (7.137) - 0.2820 (7.163)
Exhaust Valve Guide Inside Diameter, in (mm) ............. 0.2805 (7.125) - 0.2815 (7.150)
Valve Spring Free Length, in (mm) ............. 1.600 (40.64)
Valve Open, in (mm) ............. 1.055 (26.80)
Valve Closed , in (mm) ............. 1.346 (34.19)

John Deere 318 Engine Tightening Torque Specs

Gearcase Cover, ft-lb (Nm) ............. 8-10 (11-14)
Cylinder Head Bolts (Asbestos Gasket), ft-lb (Nm) ............. 16-18 (22-24)
Cylinder Head Bolts (Graphoil Gasket), ft-lb (Nm) ............. 14-16 (19-22)
Rear Bearing Plate Screws, ft-lb (Nm) ............. 25-27 (34-37)
Starter Mounting Bolts, ft-lb (Nm) ............. 24-26 (33-35)
Connecting Rod Bolt, ft-lb (Nm) ............. 14 (19)
Flywheel Cap Screw, ft-lb (Nm) ............. 50-55 (67-75)
Other 1/4" Cylinder Block Stud and Nuts, ft-lb (Nm) ............. 7-9 (10-12)
Other 5/16" Cylinder Block Stud and Nuts, ft-lb (Nm) ............. 8-10 (11-14)
Oil Base, ft-lb (Nm) ............. 18-23 (24-31)
Intake Manifold Mounting Screws, ft-lb (Nm) ............. 6-10 (8-14)
Oil Pump, ft-lb (Nm) ............. 7-9 (10-12)
Valve Cover, ft-lb (Nm) ............. 1-2 (1-3)
Exhaust Manifold Mounting Screws, ft-lb (Nm) ............. 9-11 (12-15)

JOHN DEERE TRACTORS ATTACHMENTS
420	430	455	790	990
X300	X320	X330	X350	X475
X485	X500	X540	X570	X590
X700	X720	X738	X758	1023E
2025R	2210	2520	3025E	3032E
3038E	3038R	3039R	3046R	3203
3320	3520	4052R	4066R	4100
4105	4115	4200	4310	4320
4400	4410	4520	4600	4720

JD TRACTORS TROUBLESHOOTING
2640	3040	3310	3650	4100
5050D	5090R	5410	6105R	7200R
E130	L111	LA110	LT155	X300R