Оценок - 4, средний балл: 4.3
(
)
)
|
Фрагмент инструкции
25). IDLE SPEED ADJUSTMENT The idle speed of the engine is adjustable. An idle adjustment screw is between the air filter cover and the engine starter housing (Fig. 29). NOTE: Careless adjustments can seriously damage your unit. Aside from the idle speed, only a Sears or other qualified service dealer should make carburetor adjustments. 1. Check Fuel Old 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. 2. 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. This is often mistaken for an out Fig. 25 Air Filter Screen Air Filter Housing Air Filter Cover Tab Hooks Air Filter Slot Fig. 26 Fig. 27 of adjustment idle. Check the condition of the air filter before adjusting the idle speed screw. Refer to Air Filter Maintenance. 3. Adjust Idle Speed Screw If, after checking the fuel and cleaning the air filter, the engine still will not idle, adjust the idle speed screw as follows: 1. Start the engine and let it run at a high idle for a minute to warm up. Refer to Starting/Stopping Instructions. 2. Move the throttle control lever to the Slow position ( ) and let the engine idle. If the engine stops, insert a small phillips in between the Air Filter Cover and the Engine Cover (Fig. 29). NOTE: Do not engage the Blade Clutch Lever while adjusting the idle speed screw to ensure that the blade will not rotate. 3. Turn the idle speed screw in, clockwise, 1/8 of a turn at a time (as needed) until the engine idles smoothly. Checking the fuel, cleaning the air filter, and adjusting the idle speed should solve most engine problems. If not and all of the following are 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. ROCKER ARM CLEARANCE This 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 every 25 hours of operation. • The engine must be cold when checking or adjusting the valve clearance. • This task should be performed inside, in a clean, dust free area. 1. Remove the six (6) screws on the back of the engine cover with a Flat-head or T-25 Torx screwdriver (Fig. 30). 2. Disconnect the spark plug wire. 3. Clean dirt from around the spark plug. Remove the spark plug from the cylinder head by turning a 5/8 in. socket counterclockwise. 4. Remove the engine cover (Fig. 30). 5. 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. 31). Remove the rocker arm cover and gasket. 6. 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. Look in the spark plug hole to view the piston (Fig. 32) • Both rocker arms move freely, and both valves are closed If these statements are not true, repeat step 6. 7. Slide the feeler gauge between the rocker arm and the top of each valve stem. Measure the clearance Fig. 28 Fig. 29 Idle Adjustment Screw Fig. 30 Remove Screws Remove Screws Fig. 31 Rocker Arm Cover Spark Plug Hole WARNING: To prevent serious personal injury, make sure the blade has stopped rotating before you turn it off. MAINTENANCE AND REPAIR INSTRUCTIONS 11 INTAKE Spark Plug Hole Feeler Gauge Rocker Arms Adjusting Screws EXHAUST 5. 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 rear engine cover. See Rocker Arm Clearance. 2. With a flat blade screwdriver or Torx T-20 bit and a T-25 bit, remove the screws attaching the spark arrestor cover to the muffler (Fig. 35). 3. Pull the tab on the Fig. 34 0.025 in. (0.635 mm) Spark Arrestor Screen MAINTENANCE AND REPAIR INSTRUCTIONS INTAKE Spark Plug Hole Feeler Gauge Rocker Arms Adjusting Screws EXHAUST 5. 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 rear engine cover. See Rocker Arm Clearance. 2. With a flat blade screwdriver or Torx T-20 bit and a T-25 bit, remove the screws attaching the spark arrestor cover to the muffler (Fig. 35). 3. Pull the tab on the Fig. 34 0.025 in. (0.635 mm) Spark Arrestor Screen MAINTENANCE AND REPAIR INSTRUCTIONS Fig. 32 between the valve stem and rocker arm (Fig. 32). Measure both the intake and exhaust valves. The recommended clearance for both intake and exhaust is .003–.006 i...