Open and support the rear end of the fuel tank (page 3-4). Remove the air cleaner housing (page 5-51).
Disconnect the intake duct control solenoid valve hose from the intake manifold.
![](https://motoinstruction.ru/img/honda/9/115672.jpg)
Remove the vacuum joint plug from the intake manifold. Connect the vacuum gauge hoses to the hose joints.
Tool: Vacuum gauge set 07LMJ-001000A.
Use tachometer with graduations of 50 rpm or smaller that will accurately indicate 50 rpm change.
Connect the tachometer.
Start the engine and let it idle until the radiator fan starts.
![](https://motoinstruction.ru/img/honda/9/115673.jpg)
1. Check the difference in vacuum between each cylinder.
- The front cylinder vacuum pressure is higher than the rear cylinder vacuum pressure: Adjust the front cylinder vacuum pressure with the rear cylinder vacuum pressure by turning in the front cylinder air screw.
- The rear cylinder vacuum pressure is higher than the front cylinder vacuum pressure: Adjust the front cylinder vacuum pressure with the rear cylinder vacuum pressure by turning out the front cylinder air screw.
Tool: Pilot screw wrench 07908-4730002.
![](https://motoinstruction.ru/img/honda/9/115674.jpg)
2. If the front cylinder air screw is 1½ turned in/out or more, adjust the rear cylinder air screw.
- 1½ turns in or more: Turn out the rear cylinder air screw 1/2 turn.
- 1½ turns out or more: Turn in the rear cylinder air screw 1/2 turn.
Then, repeat the step 1.
3. Stop the engine.
Disconnect the vacuum gauge hoses from the hose joints.
Connect the intake duct control solenoid valve hose to the intake manifold.
Install the vacuum joint plug from the intake manifold.
Install the air cleaner housing (page 5-51).
Close the fuel tank.
Start the engine and let it idle.
4. Turn the throttle stop screw as required to obtain the specified idle speed.
Idle speed: 800±100 rpm.
Stop the engine.
![](https://motoinstruction.ru/img/honda/9/115675.jpg)