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Section 4 ADJUSTMENTS   (con't)

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The governor controls the engine speed from idle through the full operating range. Idle speed should be no lower than 1000 RPM and top no load speed should be no higher than 3800 RPM. See illustration to adjust governor.

Governed Idle Speed Adjustment

The shorter spring keeps the engine on governor, even at idle speed. If moderate loads are applied at idle, the engine will not stall.

First make final carburetor mixture adjustments. Then place remote control in idle position. Hold throttle shaft in closed position and adjust idle speed screw to 1000 RPM. Release the throttle. With remote control in idle position, adjust upper elastic stop nut to 1200 RPM.


Engine speed is controlled by movement of the control lever. To adjust: Move control lever to HIGH speed position. Loosen screw on swivel. Move wire through swivel until desired operating speed is obtained. Retighten swivel screw, bend loose end of wire around swivel. Cut off excess wire.
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These engines are single cylinder, L-head, air-cooled type

Model Series 243431 to 243434
Bore  3-1/16"
Stroke 3-1/4"
Displacement 23.94 cu. in
Horsepower 10.0 max. @ 3600 RPM
Torque ( Ft. Lbs.) 16.75 max. @ 2400 RPM

The horsepower ratings listed above are established in accordance with the Society of Automotive Engineers Test Code-J607. For practical operation, the horsepower loading should not exceed 85% of these ratings. Engine power will decrease 3% for each 1000 feet above sea level and 1% for each 10 above 60 F.


Spark Plug Type A. C. Autolite Champion
Short Plug CS-45 A7N CJ-8
Long Plug GC-46 A71 J8
Spark Plug Gap .030"
Ignition Point Gap .020"
Intake Valve Clearance .007" - .009"
Exhaust Valve Clearance .017" - .019"


Engines stored for over 30 days should be completely drained of fuel to prevent gum deposits forming on essential carburetor parts, fuel filter, fuel lines and tank.

a. Remove filter bowl, open shut-off valve and drain tank completely.

b. Replace filter bowl. Leave fuel valve open.

c. Operate engine until it stops from lack of fuel.

d. While engine is still warm, drain and clean the oil sump. Refill with fresh oil.

e. Remove spark plug, pour one ounce of SAE 30 oil into cylinder and crank slowly to spread oil. Replace spark plug.

f. Clean dirt and chaff from cylinder, cylinder head fins and blower housing.

Major engine repairs should not be attempted unless you have the proper tools and a thorough knowledge of internal combustion engines.


[Source:  Briggs & Stratton Operating and Maintenance Instructions, Models 243431 to 243434, Form No. 27030 - 74.]



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