MAINTENANCE & REPAIR INSTRUCTIONS
CARBURETOR SETTING
The idle speed of the engine is adjustable through the air filter/muffler cover. See Figure 26.
NOTE: Careless adjustments can seriously damage your unit. An authorized service dealer should make carburetor adjustments.
Check Fuel Mixture
Old or dirty fuel is usually the reason for improper unit performance. Drain and refill the tank with fresh 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.
Adjusting the Idle Speed
WARNING: The cutting head may spin during idle speed adjustment. 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.
2.Release the throttle trigger and let the engine idle. If the engine stops, engage the idle speed screw with a small screwdriver. See figure 26. Turn the idle speed screw in, clockwise, 1/8 of a turn at a time (as needed) until the engine idles smoothly.
NOTE: The cutting head should not rotate when the engine idles.
Idle Speed Screw
FIGURE 26
3.If the cutting head 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.
These procedures should solve most engine problems. If this isn’t the case, and:
•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 the unit is turned off, make sure the cutting head has stopped before you set down the unit. This will help prevent serious personal injury.
ROCKER ARM CLEARANCE
This procedure requires disassembly of the engine. If you feel unsure or unqualified to perform this, take the unit to an authorized service center.
NOTE: Inspect the valve to rocker arm clearance with a feeler gauge after the first 10 hours of operation and then every 25 hours of operation thereafter.
•The engine must be cold when checking or adjusting the valve clearance.
•This task should be performed inside, in a clean, dust free area.
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