Craftsman 316.794830 manual Idle Speed Adjustment, Intake

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. 27). NOTE: Careless adjustments can seriously damage your unit. A Sears

or other qualified service dealer should make carburetor adjustments.

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.

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 of adjustment carburetor. Check the condition of the air filter before adjusting the idle speed screw. Refer to Air Filter Maintenance.

Adjust Idle Speed Screw

WARNING: This unit will need to be running during idle speed adjustment. Wear protective clothing and observe all safety instructions to prevent serious personal injury.

Muffler

Cover

\

Starter

Housing

Screws (2)

Starter

Housing

(4)

Muffler Cover

Screws (2)

Fig. 28

Also, DO NOT set unit on any surface except a clean, hard area while starting or performing any adjustments. Debris, such as gravel, sand, dust, grass, etc., could be thrown by the blower tube and damage property or cause serious injury to bystanders or operator.

If, after checking the fuel and cleaning the air filter, the engine still will not

• The piston is at the top of its travel
by looking in the spark plug hole
(Fig. 30)
• Both rocker arms move freely, and	Spark
both valves are closed.
If these statements are not true, repeat	Plug Hole
this step.

Arm

Cover

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.Release the trigger and let the engine idle. If the engine stops, insert a small phillips screwdriver in between the Air Filter Cover and the Engine Cover (Fig. 27). 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:

Idle Speed Few

7.Slide the feeler gauge between the rocker arm and the valve

return spring. Measure the clearance between the valve stem

and rocker arm (Fig. 30 & 31). Measure both the intake and exhaust valves.

INTAKE

Rocker Arms

Fig. 29

Adjusting Nuts

O-Ring

• the engine will not idle -- Fig. 27 --

•the engine hesitates or stalls on acceleration

•there is a loss of engine power

take the unit to a Sears or other qualified service dealer.

ROCKER ARM CLEARANCE

This requires disassembly of the engine. If you feel unsure or unqualified to perform this, take the unit to a Sears or other qualified service dealer.

NOTE: Inspect the valve to rocker arm clearance with a feeler gauge after the first 10 hours of operation and every 40

hours of operation.

•The engine must be cold when checking or adjusting the rocker arm clearance.

•This task should be performed inside, in a clean, dust free area.

1.Remove the 2 muffler cover screws with a flat blade or T-25 Torx head screwdriver (Fig. 28), then remove the cover.

2.Remove the 6 starter housing screws with flat blade or T-25 Torx head screwdriver (Fig. 28), then remove the housing.

NOTE: Make sure to store the screws so that they can be reinstalled into their original holes.

3.Disconnect the spark plug wire.

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

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. 29). Remove the rocker arm cover and gasket.

6.Turn the flywheel slowly to bring the piston to the top of its travel (known as top dead center). Check that:

Feeler Gauge

Fig. 30

Adjusting Nut

Rocker Arm

.003-.006 in. (0.076-0.152 mm)

Feeler Gauge

Valve Stem

Fig. 31

12