SECTION 7: MAINTENANCE AND REPAIR INSTRUCTIONS
Carburetor Adjustment
The idle speed of the engine is adjustable through the air filter/muffler cover. See Figure 43.
NOTE: Careless adjustments can seriously damage your unit. An authorized service dealer should make carburetor adjustments.
Check Fuel Mixture
Old and/or improperly mixed fuel is usually the reason for improper unit performance. Drain and refill the tank with fresh, properly mixed fuel prior to making any adjustments. Refer to Oil and Fuel Information.
Clean Air Filter
The condition of the air filter is important to the operation of the unit. A dirty air filter will restrict air flow and change the air/fuel mixture. This is often mistaken for an out of adjustment carburetor. Check the condition of the air filter before adjusting the idle speed screw. Refer to Air Filter Maintenance.
NOTE: The cutting attachment should not rotate when the engine idles.
3.If the cutting attachment rotates when the engine idles, turn the idle speed screw counterclockwise 1/8 of a turn at a time (as needed), to reduce idle speed.
Checking the fuel mixture, cleaning the air filter, and adjusting the idle speed should solve most engine problems.
If this is not the case and the following are all true:
•The engine will not idle
•The engine hesitates or stalls on acceleration
•There is a loss of engine power
Have the carburetor adjusted by an authorized service dealer.
WARNING: After turning the unit off, make sure the cutting attachment has stopped before setting the unit down. This helps prevent serious personal injury.
Adjust Idle Speed
WARNING: The cutting attachment may spin during idle speed adjustments. Wear protective clothing and observe all safety instructions to prevent serious personal injury.
If, after checking the fuel mixture and cleaning the air filter, the engine still will not idle, adjust the idle speed as follows.
1.Start the engine and let it run at a high idle for a minute to warm up. See Starting/Stopping Instructions.
2.Release the throttle trigger and let the engine idle. If the engine stops, insert a small Phillips or flat blade screwdriver into the hole in the air filter/muffler cover. See Figure 43. Turn the idle speed screw in, clockwise, 1/8 of a turn at a time (as needed) until the engine idles smoothly.
Idle Speed Screw
Replacing the Spark Plug
Use a Champion RDJ7Y spark plug (or equivalent). The correct air gap is 0.020 inch (0.5 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 it from the spark plug.
2.Clean 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 0.020 in. (0.5 mm) using a feeler gauge. See Figure 44.
CAUTION: Do not sand blast, scrape or clean electrodes. Grit in the engine could damage the cylinder.
4.Install a
If using a torque wrench torque to:
Do not over tighten.
0.020 in.
(0.5 mm)
Figure 44
Figure 43
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