Idle Speed Inspection
- Refer to the Idle Speed Inspection in the Periodic Maintenance chapter.
Engine Vacuum Synchronization Inspection/Adjustment
- Refer to the Engine Vacuum Synchronization Inspection in the Periodic Maintenance chapter.
Throttle Body Assy Removal
Warning: Gasoline is extremely flammable and can be explosive under certain conditions. Turn the ignition switch OFF. Disconnect the battery (-) cable terminal. Do not smoke. Make sure the area is well-ventilated and free from any source of flame or sparks; this includes any appliance with a pilot light. Be prepared for fuel spillage: any spilled fuel must be completely wiped up immediately.
Remove:
- Fuel Tank (See Fuel Tank Removal)
- Air Cleaner Housing (See Air Cleaner Housing Removal)
- Fuel Hose (See Fuel Hose Replacement in the Periodic Maintenance chapter)
- Open the clamps [A].
- Disconnect the connectors [B].
Remove:
- Main Throttle Sensor Connector [A]
- Vacuum Hose [B]
- Loosen the throttle body assy holder clamp bolts [A] on both sides.
- Remove the throttle case [A] to make a throttle cable slack.
- Remove the throttle cable lower ends [A] from the throttle pulley.
- Pull off the throttle body assy from the holder.
- After removing the throttle body assy, stuff pieces of lint -free, clean cloths into the throttle body assy holders.
Caution: If dirt gets into the engine, excessive engine wear and possible engine damage will occur.
If the throttle body assy is to be disassembly, loosen the air cleaner duct clamp screws [A], and remove the air cleaner duct [B].
Throttle Body Assy Installation
If the air cleaner duct [A] was removed, install it.
Install the duct clamp screws [B] in the direction as shown. Bolt Heads [C]
- Install the throttle body assy holder clamp bolts [A] in the direction as shown.
- Bolt Heads [B]
- Run the leads and hoses as shown in the Cable, Wire, and Hose Routing section of the Appendix chapter.
- Fit the accelerator cable end [A] and the decelerator cable end [B] into the throttle pulley.
- Check fuel leakage from the throttle body assy.
Warning: Fuel spilled from the carburetors is hazardous.
- Apply a thin coating of grease to the throttle cable upper ends.
- Install the upper ends [A] of the throttle cables in the grip.
- Fit the projection [B] of the right switch housing into the hole [C] of the handlebar.
- Turn the throttle grip and make sure that the throttle valves move smoothly and return by spring force.
- Check the throttle grip free play (See Throttle Control System Inspection in the Periodic Maintenance chapter).
Warning: Operation with an incorrectly routed cable could result in an unsafe riding condition.
Adjust:
- Throttle Grip Free Play (See Throttle Control System Inspection in the Periodic Maintenance chapter)
- Idle Speed (See Idle Speed Adjustment in the Periodic Maintenance chapter)
- Throttle Body Assy Disassembly
Caution: Do not remove, disassemble or adjust the main throttle sensor [A], subthrottle sensor [B], subthrottle valve actuator [C], throttle link mechanism [D] and throttle body assy [E], because they are adjusted or set at the manufacturer. Adjustment of these parts could result in poor performance, requiring replacement of the throttle body assy.
Caution: Never drop the throttle body assy, especially on a hard surface. Such a shock to the body assy can damage it.
Remove:
- Throttle Body Assy (See Throttle Body Assy Removal)
- Screws [A]
- Delivery Pipe [B]
- Fuel Injectors [C]
Throttle Body Assy Assembly
- Replace the O-rings [A] and seals [B] with the new ones.
- Before assembling, blow away dirt or dust from the throttle body and delivery pipe by applying compressed air.
- Apply engine oil to the new O-rings of each injector [C], insert them into the delivery pipe and confirm whether the injectors turn smoothly or not.
- Install the injectors along with the delivery pipe assy into the throttle bodies.
- Install the throttle body assy (See Throttle Body Assy Installation).
