Rocker ARM Clearance, Idle Speed Adjustment


6.	Replacethefilter(Fig25). .			Checking		the	fuel,	cleaning the air filter, and adjusting the idle
NOTE:Iftheunitisoperatedwithoutthe				speed should			solve most engine problems. If not and all of the
7.	airfilter,youwillVOIDthewarranty.			following		are true:
	ReinstalltheairfiltercoverPosition.			• the engine will not idle
	theslotsonthetopoftheairfilter			•	the engine		hesitates		or stalls on acceleration
	coverontothetabsatthetopofthe			•	there is a loss of			engine power
8.	backplate(Figs25&29).	.		Have the carburetor				adjusted by a Sears or other qualified service dealer.
	Swingthecoverdownuntilthetab			ROCKER		ARM CLEARANCE
	ontheairfilterbackplatesnaps			This requires disassembly of the engine. If you feel unsure or unqualified
	intoplaceintheslotontheairfilter
				to perform this, take the unit to a Sears or other qualified service dealer.
	cover(Fig29). .		Fig. 26
				NOTE: Inspect the valve to rocker arm clearance with a feeler

					gauge after 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 seven		(7) screws on the back of the engine cover
					with a Flat-head or T-25 Torx screwdriver (Fig. 31).

Fig. 27

Fig. 28

IDLE SPEED ADJUSTMENT

Air Filter Cover

Air Filter

.... Back Plate

Fig. 29

The idle speed of the engine is

Remove

Fig. 31

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. 31).

5.Clean dirt from around the rocker

adjustable. An idle adjustment screw is between the air filter cover and the

engine starter housing (Fig. 30).

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

_ Adj/d_eent

_ Screw

arm cover. Remove the screw		Rocker
holding	the rocker arm cover with a	Arm
large flat	blade screwdriver or Torx T-	Cover

25 bit (Fig. 32). Remove the rocker arm cover and gasket.

6.Pull the starter rope slowly to bring Spark

the piston to the top	of its travel,	Plug
(known as top dead	center). Check	Hole
that:

• The piston is at the top of its travel.

Old fuel is usually the reason for
improper	unit	performance.	Drain	Fig. 30
and refill	the	tank with fresh	fuel	Fig. 30

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 of adjustment carburetor. 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.Release the throttle trigger and let the engine idle. If the engine stops, insert a small phillips in between the Air Filter Cover and the Engine Cover (Fig. 30). Turn the idle speed screw in, clockwise, 1/8 of a turn at a time (as needed) until the engine idles smoothly.

Look in the spark plug hole to view

the piston (Fig. 33).

• Both	rocker	arms move freely, and	Fig. 32
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 between the valve stem and

rocker arm (Fig. 33). Measure both the intake and exhaust valves. The recommended clearance for both intake and exhaust is .003 -

.006 in. (.076 - 0.152 mm). Use a standard automotive .005 in. (0.127 mm) feeler gauge. The feeler gauge should slide between the rocker arm and valve stem with a slight amount of resistance, without binding. See Figures 33 and 34.

8.If the clearance is not within specification:

a. Turn the adjusting nut using a 5/16 inch (8 mm) wrench or nut driver (Fig. 33).

•To increase clearance, turn the adjusting nut counterclockwise.

•To decrease clearance, turn the adjusting nut clockwise.

Replacethefilter(Fig25). .

coverontothetabsatthetopofthe

ROCKER

ARM CLEARANCE

cover(Fig29). .