Front Upper Valve Body

FRONT UPPER VALVE BODY

DISASSEMBLY





1. Remove throttle valve keep plate.





2. Using screwdriver with vinyl tape or the like wound around its tip, hold cut back valve plug and remove cut back retainer with magnet. Then remove cut back plug, cut back valve and cut back valve spring.





3. Remove one cover bolt on front valve end cover and loosen the other to move cover as shown in figure. Remove secondary regulator valve sub assembly and secondary regulator valve spring. Then remove remaining loose cover bolt to remove front valve end cover.

CAUTION: When moving cover, be sure to hold valve with finger to prevent secondary regulator valve sub assembly from jumping out.





4. Remove throttle cam bolt and then remove throttle valve cam, throttle cam return spring and cam spacer.





5. With throttle valve held as shown in figure, remove locating pin with magnet and then remove throttle valve and throttle valve primary spring.





6. Remove throttle valve and then remove throttle valve secondary spring and throttle valve compensating ring(s).

NOTE: Write down how many throttle valve compensating rings there were, for throttle pressure varies with number of them.

ASSEMBLY
Assemble each component by reversing disassembly procedure and noting following points.








- Coil outer diameter and free length of each valve spring should be as listed. Be sure to use each one of correct size.





- Install as many throttle valve compensating rings as written down when disassembled.
- Tighten throttle cam bolt to specified torque.
Throttle cam bolt tightening torque:
7.5 Nm (0.75 kg-m, 5.5 ft. lbs.)





- Tighten pressure relief valve bolts to specified torque.
Pressure relief valve bolt tightening torque:
5.5 Nm (0.55 kg-m, 4.0 ft. lbs.)