MOTOKU Carburetor Replacement Kit Instruction Manual

1. Product Overview

This MOTOKU carburetor replacement kit is designed to restore optimal performance to compatible Stihl chainsaws. It provides a direct replacement for the original carburetor, along with essential components for a comprehensive fuel system overhaul.

2. Package Contents

Please verify that all items listed below are present in your package:

• 1x Carburetor
• 2x Gaskets
• 1x Spark Plug
• 1x Fuel Filter
• 2x Fuel Hoses
• 1x Primer Bulb with Fuel Line

Image 2.1: Complete MOTOKU Carburetor Replacement Kit, showing the carburetor, gaskets, spark plug, fuel filter, fuel hoses, and primer bulb.

3. Compatibility

This carburetor replacement kit is compatible with the following Stihl chainsaw models:

• Stihl MS192
• Stihl MS192T
• Stihl MS192TC

It is designed to replace Zama C1Q-S258 carburetors and OEM part number 1137-120-0650.

4. Installation and Setup

Important Safety Note: Before beginning any installation or maintenance, ensure the chainsaw engine is cool, the spark plug wire is disconnected, and the fuel tank is empty. Wear appropriate personal protective equipment, including gloves and eye protection.

1. Preparation: Carefully remove the chainsaw's engine cover and air filter housing to access the existing carburetor. Document the routing of all fuel lines and linkages, preferably with photographs, before disconnection.
2. Remove Old Carburetor: Disconnect the fuel lines, throttle linkage, and choke linkage from the old carburetor. Remove the mounting bolts and carefully detach the old carburetor and gaskets.
3. Install New Gaskets: Place the new gaskets in their correct positions between the engine, carburetor, and air filter housing. Ensure they are properly aligned to prevent air leaks.
4. Mount New Carburetor: Position the new MOTOKU carburetor and secure it with the mounting bolts. Do not overtighten.
5. Connect Linkages and Fuel Lines: Reattach the throttle and choke linkages. Connect the new fuel hoses and primer bulb according to your documented routing. Ensure all connections are secure and free of kinks. Replace the old fuel filter with the new one provided, ensuring it is correctly seated in the fuel tank.
6. Install New Spark Plug: Remove the old spark plug and install the new spark plug provided in the kit. Tighten to manufacturer specifications.
7. Final Assembly: Reinstall the air filter housing and engine cover.
8. Initial Start-up and Adjustment: Fill the fuel tank with the correct fuel mixture. Prime the carburetor using the primer bulb until fuel is visible. Start the chainsaw according to the manufacturer's instructions. The carburetor may require fine-tuning of the idle and high-speed mixture screws for optimal performance. Refer to your chainsaw's original manual for specific adjustment procedures.

Image 4.1: Side view of the carburetor, showing fuel line connections.

Image 4.2: Angled view of the carburetor, highlighting adjustment screws.

Image 4.3: Top view of the carburetor, showing the air intake and choke mechanism.

Image 4.4: Opposite side view of the carburetor, detailing the throttle linkage.

5. Operation

Once the carburetor is installed and the chainsaw is reassembled, operate the chainsaw according to the original manufacturer's instructions. Ensure proper fuel mixture and chain lubrication are maintained for safe and efficient operation.

6. Maintenance

Regular maintenance of your chainsaw's fuel system is crucial for longevity and performance. Consider the following:

• Fuel Filter: Inspect and replace the fuel filter periodically, especially if fuel flow issues are observed.
• Air Filter: Keep the air filter clean to ensure proper air-fuel mixture.
• Spark Plug: Check the spark plug for wear and proper gap. Replace if fouled or worn.
• Fuel Quality: Always use fresh, properly mixed fuel. Stale fuel can cause carburetor issues.

7. Troubleshooting

If you encounter issues after installing the new carburetor, consider these common troubleshooting steps:

• Chainsaw Will Not Start:
  • Verify spark plug connection and condition.
  • Check fuel lines for kinks or blockages.
  • Ensure the primer bulb is functioning and fuel is reaching the carburetor.
  • Confirm choke lever is correctly engaged for starting.
• Engine Runs Poorly or Stalls:
  • Adjust the carburetor's idle and mixture screws. Small adjustments can significantly impact performance.
  • Check for air leaks around the carburetor mounting area or intake manifold.
  • Ensure the air filter is clean.
• Choke Lever Fitment Issues: Some users have reported that the original Stihl choke lever may not perfectly fit the replacement carburetor's choke shaft. If this occurs, it may be necessary to adapt the existing lever or ensure the choke mechanism can be manually operated for starting.

8. Specifications

• Brand: MOTOKU
• Compatible OEM Part: 1137-120-0650
• Replaces Zama Model: C1Q-S258
• Item Weight: Approximately 7 ounces (carburetor only)
• Package Dimensions: Approximately 5.47 x 5.35 x 1.57 inches
• UPC: 749029997051

9. Safety Information

Working with chainsaws and fuel system components carries inherent risks. Always prioritize safety:

• Always disconnect the spark plug wire before performing any work on the chainsaw.
• Ensure the engine is cool to the touch before handling components.
• Work in a well-ventilated area when handling fuel.
• Keep open flames and ignition sources away from fuel and fuel system components.
• Wear appropriate personal protective equipment, including safety glasses and gloves.
• Refer to your chainsaw's original owner's manual for comprehensive safety guidelines.

10. Warranty and Support

For information regarding product warranty, returns, or technical support, please refer to the seller's policies or contact MOTOKU customer service directly through their official channels. Keep your purchase receipt as proof of purchase.