MAINTENANCE AND REPAIR INSTRUCTIONS

3.Remove the screw behind the engine cover (Fig. 52).

Screw

Fig. 52

4.Disconnect the spark plug wire.

5.Clean dirt from around the spark plug. Remove the spark plug from the cylinder head by turning a 5/8 in. socket counterclockwise.

6.Remove the engine cover (Fig. 52).

7.Clean dirt from around the rocker arm cover. Remove the screw holding the rocker arm cover with a large flat blade screwdriver or Torx T-25 bit

(Fig. 53). Remove the rocker arm cover and gasket.

Rocker Arm Cover

Spark Plug Hole

Fig. 53

8.Pull the starter rope slowly to bring the piston to the top of its travel, (known as top dead center). Check that:

•The piston is at the top of its travel while looking in the spark plug hole (Fig. 53)

•Both rocker arms move freely, and both valves are closed

If these statements are not true, repeat this step.

9.Slide the feeler gauge between the rocker arm and the valve return spring. Measure the clearance between the valve stem and rocker arm (Fig. 54). Measure both the intake and exhaust valves.

The recommended clearance for the intake and exhaust is .003 – .006 in. (.076 – 0.152 mm).

Use a standard automotive feeler gauge at .005 in. (0.127mm). The feeler gauge should slide between the rocker arm and valve stem with a slight amount of resistance, without binding. Figure 54 shows how to measure the clearance, while Figure 55 shows the measured clearance.

Adjusting Nuts

Rocker Arms

INTAKE

EXHAUST

Feeler Gauge

Fig. 54

Exhaust

Adjusting Nut

Exhaust

Rocker Arm

Exhaust

Clearance:

.003–.006 in.

(.076–0.152 mm)

Intake Valve

Feeler Gauge

Stem

 

Intake Clearance:

 

.003–.006 in.

 

(.076–0.152 mm)

Exhaust Valve Stem

 

Fig. 55

10.If the clearance is not within specification:

a.Turn the adjusting nut using a 5/16 inch (8 mm) wrench or nut driver (Fig. 55).

•To increase clearance, turn the adjusting nut counterclockwise.

•To decrease clearance, turn the adjusting nut clockwise.

b.Recheck both clearances, and adjust as necessary.

11.Reinstall the rocker arm cover using a new gasket. Torque the screw to 20–30 in•lb (2.2–3.4 N•m).

12.Reinstall the engine cover. Check alignment of the cover before tightening the screws. Tighten screws.

13.Reinstall the muffler cover. Slip the rear tab on the muffler cover into the engine cover rear slot. Then slide the remaining slots into the tabs until they snap into place (Fig. 50).

14.Check the spark plug and reinstall. See Replacing the Spark Plug.

15.Replace the spark plug wire.

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