3. Remove the fan housing.

_

4.Use a 9!16" socket wrench on the flywheel nut to keep the crankshaft from moving.

Figure54.'

NOTE: Place the socket handle forward as shown in Figure 54.

5.Remove the clutch with a 314,. socket or end wrench in a clockwise direction:. Figure 55.

KEEP

CRANKSHAFT

FROM MOVING

Figure 54

E. CARBURETOR ADJUSTMENTS

The carburetor has been adjusted at the fac- tory for sea level conditions. Adjustment may become necessary if the unit is used at significantly higher altitudes or if you notice anyof the following conditions:

--Chainmoves with the engine at idle speed. --Loss of cutting power which is not cord

rected by air filter or muffler screen clean-

.... ing.

--Enginedies or hesitates when it should accelerate.

Permanent damage will occur to the engine if incorrect carburetor adjustments are made. To make the adjustment, follow the procedure below very carefully.

 

 

WARNING!

 

l

The chainmay be moving during this procedure.

]

Wear your protective gear and observe all of the

safety

precautions.

 

1. PREPARATION

:"

 

a.

Stop engine.

 

 

b. Use a fresh fuel mixture with proper

 

 

gasolineloil

ratio.

 

 

C,

Place the

saw on a

solid, flat surface and

 

make sure the chain will not contact any object.

d. Locate the three (3) Carburetor adjusting screws located on the fan housing side of the saw. Figure 56.

e.Turn the Low Speed Mixture Screw and the

High Speed Mixture Screw clockwise

just until they stop. Do not turn the screws

until they are tight as you may damage

22the needle seats.

[CAUTION:IDo not remove the clutch with a

punch or a power tool to avoid clutch damage orbreakage.

6, Remove worn sprocket and replace.

7.install clutch in a counterc/ockwise direction.

Figure 55,

8.Hold flywhee! bY hand and torque clutch to 22 ft. pounds.

NOTE: Do not hold a wrench on the flywheel nut when replacing the clutch, This could loosen the flywheel nut.

9.Reinstall fan housing, bar chain and bar clamp.

\

CLOCKWISE

INSTALL CLUTCH

COUNTERCLOCKWI SE

Figure 55

i ii':

f. Turn the LowSpeed Mixture Screw and the

HighSpeed

Mixture

S-c-few one full turn

. €ounterClockwise

_

:

i

..... i

 

' m

 

 

i

i

i

,,

_:_"

 

 

 

HIGH

 

\

 

 

 

_:SPEED !

 

ADJ.

 

 

 

ADJ.

 

SCRE_

 

 

 

 

 

 

IDLE

 

 

 

1

 

 

SPEED ADJ. SCREW t

 

 

 

 

 

II Ir

i iii

 

 

I

i ii

ml i

....

Figure 56

 

 

,

 

 

2.IDLE SPEED ADJUSTMENT--!

a. Start the engine and allow to idle.

b. Adjust ff the engine dies or stopsby itu rning the Idle Speed Screw 1/2 _turnclockwise

NOTE::To increase idle speed, turn the Idle

Speed Screw clockwise _To

decrease idle speed, turn the Idle Speed

Screw counterclockwise

c. Run the engine for a few minutes to bring it up to operating temperature.

NOTE: The engine must beat operating

temperature for proper adjustments to be made.

3.LOW SPEED MIXTURE ADJUSTMENT

a. Turn the Low Speed Mixture Screw slowty

clockwise _ until the RPM starts to

drop. Note the position.

b. Turn the LowSpeed Mixture Screw coun-

terclockwise _ until the RPM speeds

up and starts to drop again. Note the posi- tion.

c. Set the Low Speed Mixture Screw at the mid*point between the two positions.

Page 22
Image 22
Sears 358.356090-3.7/20, 358.356100-3.7/18PS manual Carburetor Adjustments, LOW Speed Mixture Adjustment