John Deere 112 Lawn & Garden Tractor Instruction Manual

1. Introduction

This manual provides essential service and maintenance information for the John Deere 112 Lawn and Garden Tractor (Serial No. 250,001 and up). It is designed to assist owners and service personnel in understanding the tractor's components and systems.

The manual is organized into sections, with each section dedicated to a specific component or operational system of the tractor. Information is grouped for clarity and ease of reference.

Emphasis is placed on diagnosing malfunctions, analysis, and testing. This includes identifying potential problems and understanding their causes. Specific components and their functionalities are analyzed to help determine the root cause of issues. This approach aids in identifying necessary repairs and replacement parts.

Specifications and special tools required for various procedures are detailed in the last group of each section.

This manual should be kept in a clean, dry location, preferably in a service manual rack or binder within your Lawn and Garden Parts and Service department.

Updates and revised pages will be provided as they become available. It is important to insert new pages into your manual promptly to ensure you always have the most current information. This practice helps maintain the manual's value as a service department asset.

Safety Alert: This safety alert symbol identifies important safety messages within this manual. Always read the message carefully and follow the instructions to prevent injury.

Image: A page from the service manual titled "INTRODUCTION," detailing the manual's purpose, structure, and safety warnings.

2. Setup and Pre-Operation

Before operating the John Deere 112 Lawn & Garden Tractor, ensure proper setup and perform pre-operation checks to guarantee safe and efficient performance.

2.1 Fuel and Oil

• Fuel: Fill the fuel tank with fresh, clean unleaded gasoline. Do not overfill. Refer to the fuel tank capacity in the specifications section.
• Engine Oil: Check the engine oil level using the dipstick. Ensure the oil level is between the "Add" and "Full" marks. Use recommended oil type as specified in the maintenance section.

2.2 Tire Pressure

Verify that all tires are inflated to the correct pressure. Incorrect tire pressure can affect stability, traction, and cutting performance.

• Front Tires: Refer to the specifications for recommended PSI.
• Rear Tires: Refer to the specifications for recommended PSI.

2.3 Safety Checks

• Ensure all safety shields and guards are in place and securely fastened.
• Test the brake system for proper function.
• Confirm that the PTO (Power Take-Off) engagement/disengagement mechanism operates smoothly.
• Check for any loose fasteners, leaks, or damaged components.

3. Operating Instructions

Follow these instructions for safe and effective operation of your John Deere 112 Lawn & Garden Tractor.

3.1 Starting the Engine

1. Ensure the transmission is in neutral and the parking brake is engaged.
2. Turn the ignition key to the "ON" position.
3. If the engine is cold, pull the choke control out fully.
4. Turn the ignition key to the "START" position. Release the key once the engine starts.
5. Gradually push the choke control in as the engine warms up.

3.2 Driving the Tractor

• Release the parking brake.
• Select the desired gear.
• Slowly release the clutch pedal while gently pressing the accelerator.
• Always operate at a safe speed, especially on uneven terrain or slopes.

3.3 Engaging the PTO

The Power Take-Off (PTO) engages attachments such as mower decks or tillers.

1. Ensure the engine is running at a low idle.
2. Engage the PTO lever smoothly.
3. Increase engine RPM to the recommended operating speed for the attachment.
4. To disengage, reduce engine RPM and pull the PTO lever back.

3.4 Stopping the Engine

1. Reduce engine speed to idle.
2. Disengage the PTO (if engaged).
3. Engage the parking brake.
4. Turn the ignition key to the "OFF" position.
5. Remove the key for security.

4. Maintenance

Regular maintenance is crucial for the longevity and optimal performance of your John Deere 112 Lawn & Garden Tractor. Always refer to the detailed service manual for specific procedures and intervals.

4.1 Engine Oil Change

• Frequency: Every 50 operating hours or annually, whichever comes first.
• Procedure:
  1. Run the engine briefly to warm the oil.
  2. Place a drain pan under the oil drain plug.
  3. Remove the drain plug and allow oil to drain completely.
  4. Replace the drain plug and refill with the recommended type and quantity of engine oil.
  5. Check the oil level with the dipstick.

4.2 Air Filter Service

• Frequency: Inspect every 25 operating hours, replace as needed or annually.
• Procedure:
  1. Remove the air filter cover.
  2. Carefully remove the air filter element.
  3. Inspect for dirt or damage. Clean or replace as necessary.
  4. Reinstall the filter and cover securely.

4.3 Spark Plug Inspection/Replacement

• Frequency: Inspect annually, replace every 100-200 operating hours or as needed.
• Procedure:
  1. Remove the spark plug wire.
  2. Use a spark plug wrench to remove the spark plug.
  3. Inspect the electrode for wear or fouling. Clean or replace.
  4. Ensure the gap is set to the specified measurement (refer to specifications).
  5. Reinstall the spark plug and wire.

5. Troubleshooting

This section provides solutions to common operational issues. For complex problems, consult a qualified service technician or refer to the detailed service manual.

5.1 Engine Will Not Start

• No Fuel: Check fuel level and refill if necessary.
• Dead Battery: Check battery terminals for corrosion, ensure connections are tight. Recharge or replace battery.
• Spark Plug Issue: Inspect spark plug for fouling or incorrect gap. Clean or replace.
• Safety Interlock: Ensure parking brake is engaged, PTO is disengaged, and operator is in the seat (if applicable).

5.2 Engine Runs Poorly or Stalls

• Clogged Air Filter: Inspect and clean or replace the air filter.
• Stale Fuel: Drain old fuel and refill with fresh gasoline.
• Dirty Carburetor: May require cleaning or adjustment by a service technician.
• Incorrect Spark Plug Gap: Check and adjust spark plug gap.

5.3 Poor Cutting Performance (if applicable)

• Dull Blades: Sharpen or replace mower blades.
• Incorrect Deck Height: Adjust mower deck to the appropriate cutting height.
• Engine RPM Too Low: Ensure engine is operating at full throttle when mowing.

6. Specifications

This section outlines key technical specifications for the John Deere 112 Lawn & Garden Tractor. These details are crucial for proper maintenance and part replacement.

6.1 Engine Specifications

Note: The horsepower rating shown is established by the engine manufacturer in accordance with standard Industrial Combustion Engine Institute procedures. It is corrected at 60°F and 29.92 in. Hg. Barometer and developed from laboratory test engines equipped with standard air cleaner and muffler, less alternator equipment.

6.2 Tire Specifications

Note: Tubes available for service. See your parts catalog.

Image: A page from the service manual detailing engine specifications including model, displacement, horsepower, and valve clearances, along with tire specifications for various codes and locations.

Image: Another page from the service manual, likely containing further detailed specifications or diagrams related to the John Deere 112 tractor.