CE8069
Briggs & Stratton
SINGLE CYLINDER OHV AIR-COOLED ENGINES
8/09
273521 Twin Cylinder OHV Air-Cooled Engines
271172 Twin Cylinder L-Head Air-Cooled Engines
270962 Single Cylinder L-Head Air-Cooled Engines
276535 Two-Cycle Snow Engines
CE8069 Out of Production Engines (1919-1981)
Repair Manuals for other
Briggs & Stratton Engines:
Single Cylinder OHV
Air-Cooled Engines
POST OFFICE BOX 702
MILWAUKEE, WI 53201 USA
©2009 Briggs & Stratton Corporation
BRIGGS&STRATTON
CORPORATION
Part No. 276781-8/09
Quality Starts With A
Master Service Technician
www.ThePowerPortal.com (Dealers)
BRIGGSandSTRATTON.COM (Consumers)
FORWARD
This manual was written to assist engine technicians and service personnel with the repair and
maintenance procedures for Briggs & Stratton engines. It assumes that persons using this manual have
been properly trained in and are familiar with the servicing procedures for these products, including the
proper use of required tools and safety equipment and the application of appropriate safety practices.
Persons untrained or unfamiliar with these procedures or products should not attempt to perform such
work.
Proper maintenance and repair is important to safe, reliable operation of all engines and engine-driven
systems. The troubleshooting, testing, maintenance, and repair procedures described in this manual are
appropriate for the Briggs & Stratton engines described herein. Alternative methods or procedures may
pose risk to personal safety and the safety and/or reliability of the engine and are not endorsed or
recommended by Briggs & Stratton.
All information, illustrations, and specifications contained in this manual were based on the data available
at the time of publication. Briggs & Stratton Corporation reserves the right to change, alter, or otherwise
improve the product or the product manuals at any time without prior notice.
Briggs & Stratton offers two complementary publications to enhance understanding of engine technology,
maintenance, and repair. (Neither publication, however, is a substitution for a recognized training program
for engine technicians.)
• For consumers, Small Engine Care & Repair (p/n 274041) provides a comprehensive overview of how
small air-cooled engines work, basic troubleshooting, and step-by-step maintenance procedures.
• For engine technicians and consumers alike, an in-depth study of engine theory and operation can be
found in the textbook Small Engines (p/n CE8020).
Both publications can be purchased at BRIGGSandSTRATTON.COM or through a local Authorized Briggs
& Stratton Service Dealer.
Copyright © 2009 Briggs & Stratton Corporation
All rights reserved.
No part of this manual may be reproduced or transmitted in any form or by any means, electronic or
mechanical, including photocopying or recording by any information storage and retrieval system, without
prior written permission from Briggs & Stratton Corporation.
6
This Engine Repair Manual includes the following
Engine Models:
• MODEL 110000 HORIZONTAL SERIES
• MODEL 120000 HORIZONTAL SERIES
• MODEL 150000 HORIZONTAL SERIES
• MODEL 200000 HORIZONTAL SERIES
• MODEL 210000 HORIZONTAL SERIES
• MODELS 97700 & 99700 VERTICAL SERIES
• MODEL 110000 VERTICAL SERIES
• MODEL 120000 VERTICAL SERIES
• MODEL 210000 VERTICAL SERIES
• MODEL 280000 VERTICAL SERIES
• MODEL 310000 VERTICAL SERIES
• MODEL 330000 VERTICAL SERIES
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5
6
8
9
10
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SECTION 1 - Safety, Maintenance and Adjustments
SECTION 2 - Troubleshooting
SECTION 3 - Exhaust Systems
SECTION 5 - Governor Systems
SECTION 6 - Cylinder Heads and Valves
SECTION 7 - Starters
SECTION 8 - Lubrication Systems
SECTION 9 - Cylinders, Covers and Sumps
SECTION 10 - Crankshafts, Camshafts, Balancing Systems, and Gear Reductions
SECTION 11 - Pistons, Rings and Connecting Rods
SECTION 12 - Engine Specifications
SECTION 4 - Fuel Systems and Carburetion
THISPROPER SERVICE AND REPAIR IS IMPORTANT
TO THE SAFE, ECONOMICAL AND RELIABLE
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SECTION 1 - SAFETY, MAINTENANCE, AND ADJUSTMENTS
ENGINE SAFETY- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4
BRIGGS & STRATTON NUMERICAL IDENTIFICATION SYSTEM - - - - - - - - - - - - - - - - - - - - - - - - - - 7
ENGINE MAINTENANCE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 8
FUEL AND OIL RECOMMENDATIONS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 8
MAINTENANCE CHART - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9
FLYWHEEL BRAKE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9
COMBUSTION CHAMBER - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 11
AIR FILTER - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 11
SNOW HOOD - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 13
OIL AND OIL FILTER - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 14
SPARK PLUG - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 14
COOLING SYSTEM - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 15
ENGINE ADJUSTMENTS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -16
ADJUST REMOTE CONTROLS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 16
GOVERNOR ADJUSTMENTS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 18
ADJUST VALVE CLEARANCE - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 21
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ENGINE SAFETY
This repair manual contains safety information
that is designed to:
• Make you aware of hazards associated
with engines.
• Inform you of the risk of injury associated
with those hazards.
• Tell you how to avoid or reduce the risk of
injury.
Signal Words in Safety Messages
The safety alert symbol ( ) is used to identify
safety information about hazards that can result
in personal injury.
A signal word (
DANGER, WARNING, or CAUTION)
is used with the alert symbol to indicate the
likelihood and the potential severity of injury. In
addition, a hazard symbol may be used to
represent the type of hazard.
DANGER indicates a hazard which, if not
avoided, will result in death or serious
injury.
WARNING indicates a hazard which, if
not avoided, could result in death or
serious injury.
CAUTION indicates a hazard which, if
not avoided, could result in minor or
moderate injury.
NOTICE indicates a situation that could
result in damage to the product.
Prior to work, read and understand the section(s)
of this manual that pertain to the job. Follow all
safety warnings.
• Wear suitable eye protection.
• When servicing engines or equipment,
prevent accidental starting by
disconnecting spark plug wire from the
spark plug(s) and disconnect negative
battery cable.
• Periodically clean engine. Keep governor
parts free of dirt, grass, and other debris
which can affect engine speed and
cooling.
• Always use fresh gasoline. Stale fuel can
cause gum deposits in the carburetor
and cause leakage, flow restrictions, or
other failures.
• Check fuel lines and fittings frequently for
cracks or leaks and replace if necessary.
Hazard Symbols and Meanings
WAR NING
Before attempting to service this equipment,
read and understand this manual and the
operating instructions of the engine and the
equipment it powers.
Failure to follow instructions could result in
property damage, serious injury (including
paralysis) or even death.
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WARNING
Briggs & Stratton does not approve or autho-
rize the use of these engines on 3-wheel All
Terrain Vehicles (ATV’s), motor bikes, fun/rec-
reational go-karts, aircraft products, or vehi-
cles intended for use in competitive events.
Use of these engines in such applications
could result in property damage, serious injury
(including paralysis), or even death.
WARNING
The engine exhaust from this product contains
chemicals known the State of California to
cause cancer, birth defects, and other repro-
ductive harm.
WARNING
Gasoline and its vapors are extremely
flammable and explosive.
Fire or explosion can cause severe
burns or death.
When adding fuel:
• Turn engine OFF and let engine cool for at least 2 minutes
before removing the fuel cap.
• Fill fuel tank outdoors or in a well-ventilated area.
• Do not overfill fuel tank. To allow for expansion of the gaso-
line, do not fill above the bottom of the fuel tank neck.
• Keep gasoline away from sparks, open flames, pilot lights,
heat and other ignition sources.
• Check fuel lines, tank, cap, and fittings frequently for cracks
or leaks. Replace if necessary.
• If fuel spills, wait until it evaporates before starting engine.
When starting engine:
• Make sure spark plug, muffler, fuel cap, and air cleaner are
in place.
• Do not crank engine with spark plug removed.
• If fuel spills, wait until it evaporates before starting engine.
• If engine floods, set choke (if equipped) to OPEN/RUN posi-
tion. Place throttle (if equipped) in FAST and crank until
engine starts.
When operating equipment:
• Do not tip engine or equipment at an angle which would
cause fuel to spill.
• Do not choke carburetor to stop engine.
• Never start or run the engine with the air cleaner assembly
(if equipped) or the air filter (if equipped) removed.
When changing oil:
• If you drain the oil from the top oil fill tube, the fuel tank must
be empty or fuel can leak out and result in a fire or explosion.
When transporting equipment:
• Transport with fuel tank empty or with fuel shut-off valve set
to OFF.
When storing gasoline or equipment with fuel in the tank:
• Store away from furnaces, stoves, water heaters, or other
appliances that have a pilot light or other ignition source
because they can ignite gasoline vapors.
WAR NING
Running engines produce heat. Engine
parts, especially mufflers, become
extremely hot.
Severe thermal burns can occur on
contact.
Combustible debris, such as leaves,
grass, brush, etc. can catch fire.
• Allow muffler, engine cylinder fins, and radiator
to cool before touching.
• Remove accumulated debris from muffler area
and cylinder fins.
• It is a violation of California Public Resource
Code, Section 4442, to use or operate the
engine on any forest-covered, brush-covered,
or grass-covered land unless the exhaust sys-
tem is equipped with a spark arrester, as
defined in Section 4442, maintained in effective
working order. Other States and Federal juris-
dictions may have similar laws. Contact the
original equipment manufacturer, retailer, or
dealer to obtain a spark arrester designed for
the exhaust system installed on this engine.
WAR NING
Unintentional sparking can result in fire
or electrical shock.
Unintentional start-up can result in
entanglement, traumatic amputation, or
severe lacerations.
Before performing adjustments or repairs:
• Disconnect spark plug wire and keep it away
from spark plug.
• Disconnect the negative (-) battery terminal.
When testing for spark:
• Use approved spark plug tester.
• Do not check for spark with spark plug
removed.
WAR NING
Engines give off carbon monoxide, an
odorless, colorless, poison gas.
Breathing carbon monoxide can cause
nausea, fainting, or death.
• Start and run engine outdoors.
• Do not start or run engine in an enclosed area,
even if doors and windows are open.
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WARNING
Starting engine creates sparking.
Sparking can ignite nearby flammable
gases.
Explosion and fire could result.
• If there is a natural or LP gas leak in the area,
do not start engine.
• Do not use pressurized starting fluids because
vapors are flammable.
WARNING
Rotating parts can contact or entangle
hands, feet, hair, clothing, or accesso-
ries.
Traumatic amputation or severe lacera-
tions can result.
• Operate equipment with guards in place.
• Keep hands and feet away from rotating parts.
• Tie up long hair and remove jewelry.
• Do not wear loose-fitting clothing, dangling
drawstrings, or items that could become entan-
gled in the equipment.
WARNING
Charging batteries produce hydrogen
gas. Do not store or charge a battery
near an open flame or device that uti-
lizes a pilot light or can create a spark.
WARNING
Kerosene and its vapors are extremely
flammable and should be handled with the
same precautions as gasoline.
WARNING
Damaged, worn, or loose fuel compo-
nents can leak fuel. Explosion or fire
could result.
• All fuel components should be in good condi-
tion and properly maintained.
• Repairs should only be made with factory
approved parts.
• Repair work should be done by a qualified
technician.
• Flexible supply lines should be checked regu-
larly to make sure they are in good condition.
WAR NING
Rapid retraction of starter cord (kick-
back) will pull hand and arm toward
engine faster than you can let go.
Broken bones, fractures, bruises, or
sprains could result.
• When starting engine, pull the starter cord
slowly until resistance is felt and then pull rap-
idly to avoid kickback.
• Remove all external equipment/engine loads
before starting engine.
• Direct-coupled equipment components, such
as but not limited to blades, impellers, pulleys,
and sprockets, must be securely attached.
WAR NING
Prolonged or repeated contact with used
motor oil could cause injury.
• Used motor oil has been shown to cause skin
cancer in certain laboratory animals.
• Thoroughly wash exposed areas with soap and
water.
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B RI GG S & ST RA TT ON
NUMERICAL IDENTIFICATION SYSTEM
YOUR KEY TO THE WORLD’S FINEST ENGINES
This chart explains the unique Briggs & Stratton numerical model designation system. It is possible to determine most of the
important mechanical features of the engine by merely knowing the model number. Here is how it works:
A. The first one or two digits indicate the approximate CUBIC INCH DISPLACEMENT.
B. The first digit after the displacement indicates the BASIC DESIGN SERIES, relating to
cylinder construction, ignition, general configuration, etc.
C. The second digit after the displacement indicates ORIENTATION OF CRANKSHAFT.
D. The third digit after the displacement indicates TYPE OF BEARINGS, and whether or
not the engine is equipped with REDUCTION GEAR or AUXILIARY DRIVE.
E. The last digit indicates the TYPE OF STARTER.
BRIGGS & STRATTON MODEL NUMBERING SYSTEM
TYPE 1234–01, The type number identifies the engines mechanical parts, color of paint, decals, governed speed, and Original Equipment
Manufacturer.
CODE
01061201, The code is the manufacturing date and is read as follows:
YEAR MONTH DAY ASSEMBLY LINE AND MANUFACTURING PLANT
01 06 12 01
Revised 12/08
FIRST DIGIT
AFTER DISPLACEMENT
SECOND DIGIT
AFTER DISPLACEMENT
THIRD DIGIT
AFTER DISPLACEMENT
FOURTH DIGIT
AFTER DISPLACEMENT
A B C D E
CUBIC INCH
DISPLACEMENT
BASIC
DESIGN SERIES
CRANKSHAFT
ORIENTATION
PTO BEARING,
REDUCTION GEAR,
AUXILIARY DRIVE,
LUBRICATION
TYPE OF STARTER
2
5
6
8
9
10
11
12
13
15
16
18
19
20
21
22
23
24
25
28
29
30
31
32
35
38
40
42
43
44
46
47
49
52
54
58
61
0
1
2
3
4
5
6
7
8
9
A to Z
0 to 4 - Horizontal Shaft
5 to 9 - Vertical Shaft
A to G - Horizontal Shaft
H to Z - Vertical Shaft
0 - Plain Bearing/DU
Non–Flange Mount
1 - Plain Bearing
Flange Mounting
2 - Sleeve Bearing
Flange Mounting
Splash Lube
3 - Ball Bearing
Flange Mounting
Splash Lube
4 - Ball Bearing
Flange Mounting
Pressure
Lubrication
5 - Plain Bearing
Gear Reduction
(6 to 1) CCW
Rotation
Flange Mounting
6 - Ball Bearing
Gear Reduction
(2 to 1) CCW
Rotation
7 - Plain Bearing
Pressure
Lubrication
8 - Plain Bearing
Auxiliary Drive
(PTO)
Perpendicular to
Crankshaft
9 - Plain Bearing
Auxiliary Drive
Parallel to
Crankshaft
A - Plain Bearing
Pressure
Lubrication
Without Oil Filter
0 - Without Starter
1 - Rope Starter
2 - Rewind Starter
3 - Electric Starter
Only
110 or 230 Volt
Gear Drive
4 - Electric Starter/
110 or 230 Volt
Gear Drive with
Alternator
5 - Electric Starter
Only
12 or 24 Volt
Gear Drive
6 - Alternator Only
7 - Electric Starter
12 or 24 Volt
Gear Drive with
Alternator
8 - Vertical Pull
Starter or
Side Pull Starter
9 - Mechanical
Starter
A - Electric Starter
12 or 24 Volt
Gear Drive with
Alternator and
Inverter
EXAMPLE - To identify Model 303447:
30 3 4 4 7
30 Cubic Inch Design Series 3 Horizontal Shaft Ball Bearing
Flange Mounting
Pressure Lubrication
Electric Starter
12 or 24 Volt Gear Drive
with Alternator
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ENGINE MAINTENANCE
Fuel and Oil Recommendations
Fuel must meet these requirements:
• Clean, fresh, unleaded gasoline.
• A minimum of 87 octane / 87 AKI
(90 RON).
• Gasoline with up to 10% ethanol
(gasahol) or up to 15% MTBE (methyl
tertiary butyl ether) is acceptable.
• NOTICE: Do not use unapproved
gasoline, such as E85. Do not mix oil in
gasoline or modify the engine to run on
alternate fuels. This will damage the
engine components and void the
engine warranty.
To protect the fuel system from gum formation,
mix a fuel stabilizer into the fuel. All fuel is not the
same. If starting or performance problems occur,
change fuel providers or change brands. This
engine is certified to operate on gasoline. The
emissions control system for this engine is EM
(Engine Modifications).
High Altitude
At altitudes over 5,000 feet (1524 meters), a
minimum 85 octane / 85 AKI (89 RON) gasoline
is acceptable. To remain emissions compliant,
high altitude adjustment is required. Operation
without this adjustment will cause decreased
performance, increased fuel consumption, and
increased emissions.
Operation of the engine at altitudes below 2,500
feet (762 meters) with the high altitude kit is not
recommended.
Fresh Start
® Fuel Cap
Some engines are equipped with a Fresh Start
®
fuel cap. The Fresh Start fuel cap is designed to
hold a cartridge (sold separately) that contains
fuel stabilizer.
Oil must meet these requirements:
• Briggs & Stratton Warranty Certified oils
are recommended for best performance.
• Other high-quality detergent oils are
acceptable if classified for service SF,
SG, SH, SJ or higher.
• Do not use special additives.
Outdoor temperatures determine the proper oil
viscosity for the engine. Use the chart (Figure 1)
to select the best viscosity for the outdoor
temperature range expected.
Figure 1
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Maintenance Chart
* In dusty conditions or when airborne debris is
present, clean more often.
Flywheel Brake
Model Series 97700, 99700, 110000, 120000
Vertical Shaft
The flywheel brake is part of the safety control
system required for some applications. While
running at FAST speed position, the flywheel
brake MUST stop the engine within three
seconds, when the operator releases the
equipment safety control.
Test Brake Torque
1. Disconnect spark plug wire.
2. Unscrew and/or pry off static guard
(A, Figure 2).
3. Unscrew and remove fuel tank (B).
Figure 2
4. Remove dipstick and oil fill tube
(A, Figure 3).
5. Unscrew and remove blower housing/
rewind assembly (B).
First 5 Hours
• Change oil
Every 8 Hours or Daily
• Check engine oil level
• Clean area around muffler and
controls
• Clean finger guard
Every 25 Hours or Annually
• Clean air filter*
• Clean pre-cleaner*
Every 50 Hours or Annually
• Change engine oil
• Check muffler and spark arrester
Annually
• Replace air filter
• Replace pre-cleaner
• Replace spark plug
• Replace fuel filter
• Clean air cooling system*
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Figure 3
6. Using a torque wrench and socket to fit the
flywheel nut, turn flywheel clockwise with
brake engaged. While turning at a steady
rate, torque reading should be 26 lb.-in.
(3 Nm) or higher.
7. If reading is low, check thickness of brake
pad. Replace brake assembly if thickness
is less than 0.09” (2.28mm).
8. If brake pad thickness is acceptable,
adjust control cable to position pad closer
to flywheel when safety control is in RUN
position.
9. Replace brake assembly if correct
adjustment cannot be made.
Inspect Brake and Switches
1. Disconnect spring from brake anchor
(A, Figure 4).
2. Disconnect stop switch wire from stop
switch (B). If engine is equipped with an
electric starter, disconnect both wires from
the starter interlock switch (C).
3. Remove two screws (D) from brake
bracket and remove bracket.
Figure 4
4. Inspect brake pad on brake lever. Replace
brake assembly if thickness is less than
0.09” (2.28mm).
5. Test stop switch as described in Section 2.
6. Test electric starter interlock switch as
described in Section 2.
Assemble Flywheel Brake
1. Install brake assembly on cylinder and
torque mounting screws to values listed in
Section 12 - Engine Specifications.
2. Install stop switch wire and bend end of
wire 90°. Install wires on interlock switch, if
equipped.
3. Install brake spring.
4. Actuate brake system to ensure proper
movement, then test brake torque as
previously described.
5. Install blower housing/rewind assembly,
install dipstick tube and dipstick, and
install fuel tank and static guard. Torque
all screws to values listed in Section 12 -
Engine Specifications.
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Combustion Chamber
Remove combustion chamber deposits every
500 hours or whenever the cylinder head is
removed.
With the piston at Top Dead Center (TDC),
scrape deposits from top of piston and upper
bore with a plastic scraper.
Remove the loosened deposits from around the
top ring land area using compressed air or a
shop vacuum and a soft bristle brush.
NOTICE: Use care to prevent debris from
entering push rod or oil return cavities in cylinder.
Do not damage bore, top of piston, cylinder
head, or cylinder head gasket surfaces.
It is not necessary to remove the discoloration
marks on the piston, valves, and/or cylinder
head. These marks are normal and will not affect
engine operation.
Air Filter
A correctly serviced air filter protects internal
engine parts from airborne dirt and dust. Poor
filter maintenance will allow dirt and dust to be
drawn into the engine, causing wear to the intake
system and contamination of the oil. Dirt in the oil
forms an abrasive mixture which wears down
moving parts.
NOTE: Snow engines do not have an air cleaner
assembly. Please refer to Snow Hood
Maintenance for disassembly procedures
NOTE: Do not use pressurized air or solvents to
clean the filter. Pressurized air can damage the
filter and solvents will dissolve the filter.
1. Disassemble air cleaner system.
2. Gently tap air filter cartridge on a hard
surface to loosen debris. Replace
cartridge if very dirty.
3. Wash foam filters and pre-cleaners in
warm, soapy water, then rinse and allow
to air dry. Saturate foam filters in clean
engine oil, then squeeze out access oil.
DO NOT OIL PRE-CLEANERS.
4. Drain and clean oil bath reservoirs, then
re-fill with clean engine oil.
5. Reassemble the air cleaner system.
Figures 5 through 16 illustrate the various air
cleaner systems found on Briggs & Stratton
single-cylinder OHV engines.
Figure 5
Figure 6
WARNING
Gasoline and its vapors are extremely
flammable and explosive.
Fire or explosion can cause severe
burns or death.
• Never start or run the engine with the air
cleaner assembly or the air filter removed.
12
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Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
13
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Figure 13
Figure 14
Snow Hood
NOTE: Snow engines do not have an air cleaner
assembly. Instead, a 1-piece or 2-piece snow
hood is installed to protect the carburetor area,
retain heat to resist carburetor icing, and provide
a mounting surface for engine controls.
Remove
1. Remove choke knob (A, Figure 15 and
Figure 16).
2. Remove fasteners and hood (B).
3. Disconnect stop switch wire (C) and
primer hose (D).
Figure 15
Figure 16
Inspection
1. Check hood for cracks or worn mounting
holes. Replace if necessary.
2. Check primer hose for brittleness or leaks
and check stop switch and wire for
damage. Replace parts as necessary.
Install
1. Connect stop switch wire (C, Figure 15)
and primer hose (D).
2. Install hood and fasteners (B).
3. Install choke knob (A) with tab under knob
fitting into slot of hood. Actuate the choke
knob to check for proper movement.
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Oil and Oil Filter
Change oil after the first 5 hours of operation.
After that, change oil after every 50 hours of
operation. Change oil more often if engine is
operated in dirty or dusty conditions, under
heavy loads, or in high ambient temperatures.
1. Remove oil drain plug from side or bottom
of engine and drain oil while the engine is
still warm.
2. Install drain plug.
3. Remove oil filter, if equipped.
• Clean surface of filter mounting adapter.
• Apply light coat of clean engine oil to new
filter gasket.
4. Screw new filter on by hand until gasket
contacts filter mounting adapter. Then
tighten an additional 1/2 to 3/4 turn.
5. Fill crankcase with the correct amount of
new oil.
6. Start engine and run at idle for a minute or
so.
7. Shut engine off and wait for oil to settle
back into the cylinder.
8. Check dipstick. If necessary, add more oil
slowly to bring level to FULL mark on
dipstick.
9. Replace oil fill cap and dipstick.
10. Start and run engine. Check for oil leaks.
Spark Plug
Spark plugs should be replaced every year.
NOTE: In some areas, local law requires using
resistor spark plugs to suppress radio frequency
interference.
1. Disconnect spark plug wire.
2. Remove and inspect spark plug for wear
and damage. Replace spark plug if
electrodes are burned away, or the
porcelain is cracked.
3. Do not blast clean spark plugs. Clean by
scraping or wire brushing, and then
washing in a commercial solvent.
4. Using a wire gage, check and set the gap
(A, Figure 15) per Section 12 -
Specifications.
Figure 17
5. Re-install spark plug and torque to values
listed in Section 12 - Specifications.
6. Connect spark plug wire.
WARNING
Gasoline and its vapors are extremely
flammable and explosive.
Fire or explosion can cause severe
burns or death.
• If you drain the oil from the top oil fill tube, the
fuel tank must be empty or fuel can leak out
and result in a fire or explosion.
• To empty the fuel tank, run the engine until it
stops from lack of fuel.
NOTICE
Do not overfill. Overfilling can cause seals
to fail, smoke from the exhaust, or
overheating due to oil foaming.
NOTICE
Spark plugs have different thread “reach”
and heat ranges. When changing a spark
plug, use only the specified replacement,
otherwise engine damage could occur.
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Cooling System
Dirt or debris can restrict air flow and cause the
engine to overheat, resulting in poor
performance and reduced engine life. Continued
operation with a clogged cooling system can
cause severe overheating and possible engine
damage. Clean these areas yearly or more often
when dust or airborne debris is present (Figures
18, 19, 20).
NOTICE: Do not use water to clean the engine.
Water could contaminate the fuel system. Use a
brush or dry cloth to clean the engine.
Figure 18 - Static Screen
Figure 19 - Rotating Screen
Figure 20 - Ducting & Cylinder Fins
WARNING
Running engines produce heat.
Severe burns can occur on contact.
• Allow muffler, engine cylinder fins, and radiator
to cool before touching.
• Remove accumulated combustibles from muf-
fler area and cylinder area.
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ENGINE ADJUSTMENTS
Remote Control Wire Travel
The remote control wire should measure 2.125”
(54 mm) when extended outside the casing
(Figure 21). After installation, the travel of the
remote control wire must be at least 1.375” (35
mm) to properly actuate the choke (on Choke-A-
Matic® systems) and the ignition stop switch (if
equipped).
Figure 21
Remote Controls
Horizontal Models 110000, 120000, 150000
1. Loosen casing clamp screw
(A, Figure 22).
2. Move throttle lever to fast position.
3. Move casing in direction of arrow until
slack is removed.
4. Tighten casing clamp screw.
Figure 22
Vertical Models 97700, 99700
1. Loosen casing clamp screw (A, Figure 23)
on intake elbow assembly.
Figure 23
2. Move equipment speed control lever (B) to
FAST position.
3. Move control wire and casing at governor
bracket to align hole (C) in carburetor
control lever with hole in carburetor control
bracket.
4. Tighten casing screw.
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Vertical Models 110000, 120000 with Primer
Carburetors
1. Loosen casing clamp screw
(A, Figure 24, Figure 25).
2. Move throttle lever to fast position.
3. Move casing in direction of arrow until
slack is removed.
4. Tighten casing clamp screw.
Figure 24
Figure 25
Vertical Models Series 110000, 120000 with
Choke-A-Matic® Carburetors
1. Loosen casing clamp screw
(A, Figure 26).
2. Move throttle lever to fast position.
3. Move casing in direction of arrow until
casing stops moving and choke lever (B)
moves to full choke position.
Figure 26
4. Tighten casing clamp screw.
Horizontal and Vertical Models 200000,
210000, 280000, 310000, 330000
1. L oosen casing cl amp screw
(C, Figure 27).
2. Set throttle control to FAST position.
3. Move governor control rack (D) until holes
are aligned (B) between control lever (A)
and the control bracket.
4. Tighten casing clamp screw.
Figure 27
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Governor Adjustments
A complete governor system adjustment
includes a static adjustment, engine warm-up,
idle and/or governed idle adjustment, and top no-
load adjustment. Be sure to complete all steps.
Static Adjustment
1. Loosen screw holding governor lever to
governor crank (A, Figure 28) or
(C, Figure 29).
2. Rotate throttle linkage from idle position to
wide open throttle. Note direction of
rotation of the governor arm attached to
the throttle linkage.
3. While holding linkage at wide open
throttle, use the appropriate tool to rotate
the governor shaft (B, Figure 29) until it
stops in the direction noted in Step 2.
4. Tighten screw holding governor lever to
governor crank per Section 12 - Engine
Specifications.
5. Before starting engine, manually actuate
throttle linkage to check for binding.
Figure 28
Figure 29
Top No Load Adjustment Vertical Models
97700, 99700
1. Place throttle (A, Figure 30 and 31) in
FAST position and insert a 1/8” (3.2 mm)
rod (B) through holes in carburetor control
bracket and lever.
Figure 30
Figure 31
2. Start engine and measure RPM using
Tachometer #19200 or #19389. Adjust
Top No Load RPM by turning screw (C).
3. Remove 1/8” (3.2 mm) rod.
NOTE: Correct Top No Load RPM for each
model-type-trim can be found in the engine
replacement data on Briggs & Stratton websites.
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Top No Load Adjustment Vertical Models
110000, 120000, 150000 with Primer
Carburetors
1. Start engine and run until it reaches
operating temperature.
2. Place throttle in FAST position.
3. Using Tachometer #19200 or #19389, and
Tang Bender #19229 or #19352, bend
Top No Load spring tang to obtain correct
Top No Load RPM (Figure 32).
NOTE: Correct Top No Load RPM for each
model-type-trim can be found in the engine
replacement data on Briggs & Stratton websites.
Figure 32
Idle and Top No Load Adjustment Vertical
Models 110000, 120000, 150000 with Choke-
A-Matic® Carburetors
1. Start engine and run until it reaches
operating temperature.
2. Place throttle in SLOW position. Hole in
lever will line up with hole in governor
control bracket (Figure 33). Insert a 1/8”
rod through holes to lock lever in this
position.
Figure 33
3. Hold throttle lever against idle speed
screw and, using Tachometer #19200 or
#19389, adjust to 1500 RPM. Release
throttle lever.
4. Using Tang Bender #19229 or 19352 bend
governed idle spring tang to obtain 1750
RPM (Figure 34).
5. Remove 1/8” rod.
Figure 34
6. Move throttle lever to FAST position. Hole
in lever will line up with hole in governor
control bracket (Figure 35). Insert a 1/8”
rod through holes to lock lever in this
position.
Figure 35
7. Using Tang Bender, bend Top No Load
spring tang to obtain correct Top No Load
RPM.
NOTE: Correct Top No Load RPM for each
model-type-trim can be found in the engine
replacement data on Briggs & Stratton websites.
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Idle and Top No Load Adjustment Horizontal
and Vertical Models 200000, 210000
1. Start engine and run until it reaches
operating temperature.
2. Place throttle in SLOW position.
3. Hold throttle lever against idle speed
screw, and, using Tachometer #19200 or
#19389, adjust screw to obtain 1300 RPM.
Release throttle lever.
4. Using Tang Bender #19229 or #19352,
bend governed idle spring tang to obtain
1750 RPM (Figure 36).
Figure 36
5. Place throttle in FAST position.
6. Adjust screw to obtain correct Top No
Load RPM (Figure 37).
Figure 37
NOTE: Correct Top No Load RPM for each
model-type-trim can be found in the engine
replacement data on Briggs & Stratton websites.
Idle and Top No Load Adjustment Vertical
Models 280000, 310000, 330000
All carburetor mixture adjustments should be
made before adjusting governor speeds.
1. Start engine and run until it reaches
operating temperature.
2. Place control lever in idle position.
3. Hold throttle in closed position with finger,
adjusting idle speed screw to 1200 RPM.
4. Release throttle.
5. Set control to 1750 RPM and bend tang
(A, Figure 38) until it contacts remote
control slide (B).
6. Using Tang Bender #19229 or 19352,
bend spring tang to obtain the correct Top
No Load RPM.
NOTE: Correct Top No Load RPM for each
model-type-trim can be found in the engine
replacement data on Briggs & Stratton websites.
Figure 38
Initial Adjustment (All Models)
1. Install idle speed screws and spring.
Install idle mixture screw and spring.
2. Turn idle mixture screw in until it just
bottoms.
3. Then back out screw 1-1/4” turn. This will
permit the engine to start.
Final Adjustment (All Models)
1. Install complete air cleaner before starting
engine. Start and run engine for five
minutes at 1/2 throttle to bring engine up
to operating temperature.
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2. Move equipment speed control to idle
position.
3. Turn idle screw to obtain 1750 RPM
minimum.
4. Then turn idle mixture screw clockwise
slowly until engine begins to slow.
5. Then turn screw opposite direction until
engine just begins to slow.
6. Then turn screw back to midpoint (Figure
39).
Figure 39
7. Install limiter cap (if equipped) on idle
mixture screw (Figure 40).
Figure 40
8. Move equipment speed control from idle to
high speed position.
9. Engine should accelerate smoothly. If it
doesn’t, open idle mixture screw 1/8 turn
open.
Adjust Valve Clearance
All Models - Except Vertical Models 110000,
120000 Early Production
NOTE: Check valve clearance while the engine
is cold.
1. Turn crankshaft counterclockwise until
piston is at top dead center on the
compression stroke. This prevents the
compression release from holding the
valves open.
2. Insert a narrow screwdriver or rod into the
spark plug hole as a gauge, then slowly
turn crankshaft counterclockwise until the
piston has moved down the bore by 1/4”
(6mm).
3. Using a feeler gauge (A, Figure 41), adjust
rocker nut to obtain the clearance as listed
in Section 12 - Engine Specifications.
4. Hold rocker nut and tighten the rocker ball
setscrew (B) to the torque valve shown in
Section 12 - Engine Specifications.
5. Check clearance again and re-adjust, if
necessary.
6. Repeat for other valve.
NOTE: On some models, the nut and setscrew
are positioned above the push rod ends.
Figure 41
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Vertical Models 110000, 120000 Early
Production
1. Using a feeler gauge (A, Figure 42) adjust
the locking hex nut (B) to obtain the
correct clearance as listed in Section 12 -
Engine Specifications.
2. Repeat for other valve.
Figure 42
- OR -
1. Loosen jam nut (A, Figure 43) at base of
rocker arm stud. Then, using a feeler
gauge (B), turn rocker arm screw (C) to
obtain the correct clearance as listed in
Section 12 - Engine Specifications.
2. Hold the screw and tighten the jam nut to
value shown in Section 12 - Engine
Specifications.
3. Check clearance again and re-adjust, if
necessary.
Figure 43
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SECTION 2 - TROUBLESHOOTING
SYSTEMS CHECK- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -25
CHECK IGNITION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 25
CHECK CARBURETION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 26
CHECK COMPRESSION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 27
ELECTRICAL SYSTEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -28
EQUIPMENT USED FOR TESTING - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 28
ALTERNATOR SYSTEM DIAGNOSIS- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 29
ALTERNATOR IDENTIFICATION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 30
FLYWHEEL IDENTIFICATION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 33
TESTING ALTERNATOR OUTPUT- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 33
.5-AMP DC ONLY ALTERNATOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 33
3-AMP DC ONLY ALTERNATOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 33
14-VOLT AC ONLY ALTERNATOR- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 34
DUAL CIRCUIT ALTERNATOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 35
TRI-CIRCUIT ALTERNATOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 36
5 & 9 AMP DC REGULATED ALTERNATOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 38
10 & 16 AMP DC REGULATED ALTERNATOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 39
20 AMP DC REGULATED ALTERNATOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 41
ELECTRIC STARTERS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -43
SYSTEM 3® AND SYSTEM 4®- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 43
12 VOLT DC STARTER MOTOR - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 45
120 VOLT AC STARTER MOTOR- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 46
BATTERIES - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -47
BATTERY AND CABLE RECOMMENDATIONS- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 47
BATTERY INSTALLATION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 47
CHARGING BATTERY- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 47
TESTING BATTERY - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 48
EQUIPMENT AFFECTING ENGINE OPERATION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -49
24
2
2
OIL GARD SYSTEMS - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 49
ENGINE WILL NOT START - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 49
ENGINE STARTS AND RUNS WITH LOW OIL - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 50
25
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2
SYSTEMS CHECK
Most complaints concerning engine operation
can be classified as one or a combination of the
following:
• Will not start
• Hard starting
• Lack of power
• Runs rough
• Vibration
• Overheating
• High oil consumption
The source of most of these symptoms can be
determined by performing a systems check in the
following order:
1. Ignition
2. Carburetion
3. Compression
This check-up can usually be done in a matter of
minutes. It is the quickest and surest method of
determining the cause of failure.
NOTE: What appears to be an engine
malfunction may be a fault of the powered
equipment rather than the engine. If the
equipment is suspect, see Equipment Affecting
Engine Operation.
1) Check Ignition
Engine Stopped
With spark plug installed, attach Ignition Tester
#19368 to spark plug lead and ground the other
end of the tester (Figure 1). Pull the starter rope
or activate the electric starter (if equipped). If
spark jumps the tester gap, you may assume the
ignition system is functioning satisfactorily.
Figure 1
Engine Running
If engine runs but misses during operation, a
quick check to determine whether the ignition is
at fault can be made by installing Ignition Tester
#19368 between the spark plug lead and spark
plug (Figure 2). If spark is good but engine
misses, install a new spark plug.
Figure 2
If spark does not occur, look for:
• Improperly operating interlock system
• Shorted equipment or engine stop switch
wire
• Incorrect armature air gap
• Armature failure
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2) Check Carburetion
Before making a carburetion check, be sure the
fuel tank has an ample supply of fresh, clean
gasoline.
Be sure the shutoff valve, if equipped, is open
and fuel flows freely through the fuel line. If fuel
fails to flow or is slow, check for plugged fuel cap
vent, fuel line restriction or plugged fuel filter.
Be sure throttle and choke controls are properly
adjusted.
If engine cranks but will not start, remove and
inspect the spark plug.
If plug is wet, look for:
• Over choking
• Excessively rich fuel mixture
• Water in fuel
• Float needle valve stuck open
• Plugged air cleaner
• Fouled spark plug
If plug is dry, look for:
• Leaking carburetor or intake manifold
gaskets
• Gummy or dirty carburetor, fuel filter, fuel
lines or fuel tank
• Float needle valve stuck closed
• Inoperative fuel pump (if equipped)
• Inoperative fuel shut off solenoid (if
equipped)
A simple check to determine if the fuel is getting
to the combustion chamber through the
carburetor is to remove the spark plug and pour
a small quantity of gasoline through the spark
plug hole. Replace the plug. If the engine fires a
few times and then stops, look for the same
conditions as for a dry plug.
Testing Fuel Shut Off Solenoid
The fuel shut off solenoid is controlled by the
equipment ignition switch. With the switch OFF,
the solenoid plunger closes, stopping the fuel
flow at the fixed main jet. With the switch in the
ON and START positions, the solenoid plunger
opens, allowing normal fuel flow. If operating
properly, the solenoid will click when the switch
is turned ON and OFF.
If solenoid does not click, the problem could be
the equipment wiring, engine wiring or the
solenoid. To determine which is the problem,
perform the following tests in the order shown.
Solenoid Plunger Test
NOTE: The solenoid requires a minimum of 9
Volts DC to function.
1. Remove the fuel shut off solenoid from the
carburetor.
2. Place a jumper wire on either terminal of a
9 Volt battery and on one of the pins of the
solenoid connector.
3. Place another jumper wire on the other pin
in the solenoid connector and on the other
terminal on the battery (Figure 3).
Figure 3
• Plunger should retract freely, or with very
light fingertip pressure.
• When battery connection is removed,
plunger should extend.
• Replace solenoid if plunger sticks or
does not move.
Solenoid Wiring Test
1. Set multimeter to DC Volts position.
2. With key switch OFF, disconnect solenoid
wiring connector (A, Figure 4).
3. Attach meter test leads (B) to pins inside
wiring connector.
Figure 4
27
2
2
4. Turn key switch ON. Meter should display
battery voltage.
If meter does not display battery voltage, the
problem is with the solenoid wiring, equipment
wire harness, or the keyswitch. Repair or replace
as required.
3) Check Compression
Use Leakdown Tester #19545 to check the
sealing capabilities of the compression
components.
Follow the instructions provided with the tester to
perform the leakdown test.
NOTE: Any air leaks at the connections or
fittings of the tester will affect the accuracy of the
test.
Listen for air leaking from the cylinder head
gasket, carburetor, exhaust system, and the
crankcase breather tube.
• Air flowing between the cylinder and
cylinder head indicates that the cylinder
head gasket is leaking.
• Air flowing from the carburetor indicates
air is leaking past the intake valve and
seat.
• Air flowing from the exhaust system
indicates air is leaking past the exhaust
valve and seat.
• Air flowing from the crankcase breather
tube or high oil fill dipstick tube indicates
air is leaking past the piston rings.
Possible Causes for Poor Compression:
• Loose cylinder head bolts
• Blown head gasket
• Burned valves, valve seats and/or loose
valve seats
• Insufficient tappet clearance
• Warped cylinder head
• Warped valve stems
• Worn bore and/or rings
• Broken connecting rod
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