REMOVAL AND INSTALLATION

Removal steps · Exhaust rocker arm assembly (Refer to ). <<A>> >>C<< 1. Valve spring retainer lock 2. Valve spring retainer >>B<< 3. Exhaust valve spring <<B>> >>A<< 4. Exhaust valve stem seal >>A<< 5. Valve spring seat · Rocker arm and shaft assembly (Refer to ). <<A>> >>C<< 6. Valve spring retainer lock 7. Valve spring retainer >>B<< 8. Inlet valve spring <<B>> >>A<< 9. Inlet valve stem seal >>A<< 10. Valve spring seat

1.Screw in special tool retainer holder attachment (MB992090) to special tool valve spring compressor (MD998772), and assemble special tool retainer holder D (MB992283). 2. caution When removing the valve spring retainer lock, leave the piston of the cylinder in the TDC (Top Dead Centre) position. The valve may fall into the cylinder if the piston is not properly in the TDC position. Install special tool MD998772 (with special tools MB992090 and MB992283 attached) to the cylinder head and compress the valve spring. Then, remove the valve spring retainer lock.

Use special tool valve stem seal pliers (MB992085) to nip the base of the stem seal (where the outside diameter is larger) securely, and remove it by twisting it to the left and right.

1. caution Valve stem seal for inlet valves and for exhaust valves are different. Be sure to install the correct ones. The valve stem seal must not be reused. Do not damage the tappet wall during assembly. Be sure to use a special tool to install the valve stem seal. Poor installation causes oil loss via valve guides. If oil is not applied, the valve stem seal may rise to the surface after it is press fitted. Apply a small amount of engine oil to the press-fit part and lip part of the new valve stem seal. 2.Use a special tool to install the valve stem seal, obeying the following procedures.

3.Special tool valve stem seal installer adjustable (MB992922) is composed of the components shown in the illustration. 1: Chuck 2: Sleeve 3: Lock nut (small) 4: Outer pipe 5: Lock nut (large) 6: Guide pin (5.9) 7: Guide pin (4.9) 8: Cap 9: Guide pin (5.4)

4.Adjust the inside chuck diameter, obeying the following procedures. (1) Install the sleeve to the chuck as shown in the illustration. (2) Install the shoulder of the valve stem seal to the chuck, aligning with the outer circumference line of the chuck as shown in the illustration. (3) Turn the sleeve to wring the chuck. (4) Stop the sleeve at the position where you can easily remove the valve stem seal by hand. (5) Use the (small) lock nut to fix the sleeve.

5.Adjust the stem seal insertion length, obeying the following procedures. (1) The position, in which the end face of the outer pipe is aligned with the outer circumference line of the chuck, is 0 mm of the insertion length. Insert the chuck and the sleeve into the outer pipe to fit the nut as shown in the illustration. (2) Turn the chuck to adjust the valve stem seal insertion length. note The insertion length can change by 1 mm per the chuck turn. To easily know how many times the chuck is turned, put the mark at the position shown in the illustration. (3) Use a vernier caliper to measure the checkpoint (L1) of the insertion length shown in the illustration. Check the insertion length. Inlet (L1): 18.6 mm Exhaust (L1): 19.8 mm (4) Use the (large) lock nut to fix the sleeve.

6.Install the cap to the chuck. 7.Apply the engine oil to the valve stem seal to set the chuck. 8.Install the valve spring seat.

9.Use the plastic hammer to insert the valve stem seal.

Install the inlet valve spring so that its painted side faces the rocker arm side. note The exhaust valve spring can be fitted either way up.