MAINTENANCE AND REPAIR INSTRUCTIONS

Adjusting Nuts

Rocker Arms

INTAKE

EXHAUST

Feeler Gauge

Fig. 66

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. 67

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. 67).

•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. 62).

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

15.Replace the spark plug wire.

REPLACING THE SPARK PLUG

Use a replacement part number 180890 spark plug. The correct air gap is 0.025 in. (0.655 mm.). Remove the plug after every 25 hours of operation and check its condition.

1.Stop the engine and allow it to cool. Grasp the plug wire firmly and pull the cap from the spark plug.

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

3.Replace cracked, fouled or dirty spark plug. Set the air gap at 0.025 in. (0.655 mm.) using a feeler gauge (Fig. 68).

0.025 in.

(0.655 mm.)

Fig. 68

WARNING: Do not sand blast, scrape or clean

electrodes. Grit in the engine could damage the cylinder.

4.Install a correctly-gapped spark plug in the cylinder head. Turn the 5/8 in. socket clockwise until snug.

If using a torque wrench torque to:

110-120 in.•lb. (12.3-13.5 N•m)

Do not over tighten.

SPARK ARRESTOR MAINTENANCE

1.Remove the muffler cover. See Rocker Arm Clearance.

2.With a flat blade screwdriver or Torx T-20 bit, remove the screw attaching the spark arrestor cover to the muffler (Fig. 69).

Muffler

Spark Arrestor Screen

Tab Screw

Spark Arrestor Cover

Slot

Fig. 69

3.Pull the tab on the spark arrestor cover out of the muffler. Remove the spark arrestor cover.

4.Remove the spark arrestor screen from the spark arrestor cover.

5.Clean the spark arrestor screen with a wire brush or replace it.

6.Reinstall the spark arrestor screen, spark arrestor cover and screw.

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