Throttle Valve Diaphragm Carburetor Rebuild Kit Installation Instructions

Tools Required:

1. Screwdrivers:

   • Flathead screwdriver
   • Phillips screwdriver

2. Wrench Set:

   • Metric combination wrenches (size may vary based on model)
   • Torque wrench (for specific torque settings)

3. Pliers:

   • Needle-nose pliers
   • Regular pliers

4. Cleaning Supplies:
   -Carburetor cleaner

   • Soft cloth or shop towels

5. Gasket Scraper:

   • Plastic or metal gasket scraper (to remove old gaskets)

6. Safety Gear:

   • Safety gloves
   • Safety glasses

Installation Steps:

1. Preparation:

   • Ensure the bike is on a stable surface and the engine is cool.
   • Disconnect the battery to prevent any electrical issues during the installation.

2. Remove the Carburetor:

   • Locate the carburetor on your bike.
   • Disconnect any hoses and cables attached to it.
   • Use the appropriate wrench to unbolt the carburetor from its position and carefully remove it from the bike.

3. Disassemble the Carburetor:

   • Take the carburetor to a clean workspace.
   • Remove the necessary components, including the throttle valve, to access the diaphragm.
   • Use a gasket scraper to carefully remove any old gaskets or debris.

4. Install the New Diaphragm:

   • Place the new throttle valve diaphragm from the rebuild kit into its designated position, making sure it is oriented correctly.
   • Reassemble the carburetor components in the reverse order of disassembly, ensuring all parts are aligned properly.

5. Reattach the Carburetor:

   • Carefully position the carburetor back onto its mounting location.
   • Secure it in place with the bolts, using a torque wrench to apply the correct torque setting as specified by the manufacturer.

6. Reconnect Hoses and Cables:

   • Reattach all hoses and cables that were disconnected earlier.
   • Double-check all connections for leaks or misalignments.

7. Final Checks:

   • Reconnect the battery.
   • Inspect the installation for any loose parts or connections.
   • Start the engine and check for smooth operation. Adjust the throttle and ensure the engine responds correctly.

Safety Note:
Always follow safety procedures when working on your motorcycle. If you are uncertain about any steps, consider consulting with a professional mechanic.

By following these instructions, you can successfully install the Throttle Valve Diaphragm Carburetor Rebuild Kit and enhance the performance of your 640 LC4 CV BST40 and BST 40 models. Happy riding!