Micro EngineRepair Manual

for docutech printing 12/12/03 3:24 PM Page 1

For Briggs & Stratton Discount Parts Call 606-678-9623 or 606-561-4983

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GENERAL INFORMATION Section 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DISASSEMBLY AND REPAIR Section 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TABLE OF CONTENTS

I

SECTION CONTENTS

II

1 Section 1

General InformationIn The Interest Of SafetyBriggs & Stratton Numerical Identification SystemEngine IdentificationFuel and Oil RecommendationsGasolineLubricationMaintenanceCheck OilChange OilAir CleanerBreather Check ValveReplace Spark PlugCooling SystemTroubleshootingSystematic CheckCheck IgnitionCheck CarburetionCheck CompressionEquipment Affecting Engine OperationHard Starting, Kickback or Will Not StartVibrationPower Loss

2 Section 2

Disassembly and RepairGeneral InformationRewind AssemblyInspect Starter RopeRemove Blower Housing Direct Drive EngineReplace Starter RopeInstall Blower Housing Direct Drive EngineRemove Blower Housing Clutch Drive EngineInstall Blower Housing Clutch Drive EngineIgnition CoilRemove CoilInstall CoilAdjust Air GapFlywheelRemove Flywheel Direct Drive EngineInstall Flywheel Direct Drive EngineRemove Flywheel Clutch Drive EngineInstall Flywheel Clutch Drive EngineFuel TankRemove Fuel TankInstall Fuel TankCylinder HeadRemove Cylinder HeadInstall Cylinder HeadMufflerReplace MufflerCarburetorRemove CarburetorInstall CarburetorIdle Speed Adjustment

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Section 1General Information

Section Contents

Page

IN THE INTEREST OF SAFETY 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BRIGGS & STRATTON NUMERICAL IDENTIFICATION SYSTEM 4. . . . . . . . . . . . . . . . . . . . . . . . .

ENGINE IDENTIFICATION 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

FUEL AND OIL RECOMMENDATIONS (Gasoline, Lubrication) 5. . . . . . . . . . . . . . . . . . . . . . . . . . . .

MAINTENANCE 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Check Oil 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Change Oil 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Air Cleaner 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Replace Spark Plug 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cooling System 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TROUBLESHOOTING 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Systematic Check 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Check Ignition (With Engine Starter) 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Check Ignition (Engine Running) 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Check Carburetion 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Check Compression 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Equipment Affecting Engine Operation 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hard Starting, Kickback or Will Not Start 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vibration 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power Loss 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The Briggs & Stratton engine is made of the finest material in a state-of-the-art manufacturing facility. Please un-derstand that Briggs & Stratton sells engines to original equipment manufacturers. It also sells to others in thedistribution chain who may sell to the ultimate consumer, an equipment manufacturer, another distributor or adealer. As a result, Briggs & Stratton does not necessarily know the application on which the engine will be placed.For that reason, carefully read and understand the operating instructions of the equipment before you repair oroperate.

You should also understand that there are equipment applications for which Briggs & Stratton does not approvethe use of its engines. Briggs & Stratton engines are not to be used on vehicles with less than 4 wheels. Thisincludes motor bikes, aircraft products and All Terrain Vehicles. Moreover, Briggs & Stratton does not approveof its engines being used in competitive events. FOR THAT REASON, BRIGGS & STRATTON ENGINES ARENOT AUTHORIZED FOR ANY OF THESE APPLICATIONS. Failure to follow this warning could result in death,serious injury (including paralysis) or property damage.

IN THE INTEREST OF SAFETY

The safety alert symbol ( ) is used to identifysafety information about hazards that can result inpersonal injury.

A signal word (DANGER, WARNING or CAUTION) isused with the alert symbol to indicate the likelihood andthe potential severity of injury. In addition, a hazardsymbol may be used to represent the type of hazard.

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DANGER indicates a hazard which, if notavoided, will result in death or seriousinjury.

WARNING indicates a hazard which, ifnot avoided, could result in death orserious injury.

CAUTION indicates a hazard which, if notavoided, might result in minor ormoderate injury.

CAUTION, when used without the alertsymbol, indicates a situation that couldresult in damage to the engine.

MovingParts

HAZARD SYMBOLS AND MEANINGS

Explosion

Toxic Fumes ShockHotSurface

Kickback

Fire

Prior to work, read and understand the section(s)of this manual that pertain to the job. Follow all safetywarnings.WEAR suitable eye protection (safety glasses,goggles or face shield when performing repair pro-cedures).PREVENT ACCIDENTAL STARTING by remov-ing spark plug wire from spark plug when servicingengine or equipment.PERIODICALLY clean engine. Keep carburetorparts free of dirt, grass and other debris which canaffect engine speed.USE fresh gasoline. Stale fuel can gum carburetorand cause leakage.CHECK fuel lines and fittings frequently for cracksor leaks. Replace if necessary.

The engine exhaust from this productcontains chemicals known to the State

of California to cause cancer, birthdefects, or other reproductive harm.

WARNING

Gasoline and its vapors are extremelyflammable and explosive.

Fire or explosion can cause severe burns ordeath.

WHEN ADDING FUEL Turn engine OFF and let engine cool at least

2 minutes before removing gas cap. Fill fuel tank outdoors or in well-ventilated

area. Do not overfill fuel tank. Fill tank to

approximately 1-1/2 inches below top ofneck to allow for fuel expansion.

Keep gasoline away from sparks, openflames, pilot lights, heat, and other ignitionsources.

Check fuel lines, tank, cap, and fittingsfrequently for cracks or leaks. Replace ifnecessary.

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 to OPEN/RUN

position, place throttle in FAST and crankuntil engine starts.

WHEN OPERATING EQUIPMENT Do not tip engine or equipment at angle

which causes gasoline to spill. Do not choke carburetor to stop engine.

WHEN STORING GASOLINE OR EQUIP-MENT WITH FUEL IN TANK Store away from furnaces, stoves, water

heaters or other appliances that have pilotlight or other ignition source because theycan ignite gasoline vapors.

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WARNING

Unintentional sparking can result in fire orelectric shock.

Unintentional start-up can result in entangle-ment, traumatic amputation, or laceration.

BEFORE PERFORMING ADJUSTMENTSOR REPAIRS Disconnect spark plug wire and keep it away

from spark plug.

WHEN TESTING FOR SPARK Use approved spark plug tester. Do not check for spark with spark plug

removed.

WARNING

Starting engine creates sparking.Sparking can ignite nearby flammable gases.

Explosion and fire could result.

If there is natural or LP gas leakage in area,do not start engine.

Do not use pressurized starting fluidsbecause vapors are flammable.

WARNING

Engines give off carbon monoxide, anodorless, colorless, poison gas.

Breathing carbon monoxide can causenausea, fainting or death.

Start and run engine outdoors. Do not start or run engine in enclosed area,

even if doors or windows are open.

WARNING

Running engines produce heat. Engine parts,especially muffler, 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 and fins to coolbefore touching.

Remove accumulated combustibles frommuffler area and cylinder area.

Install and maintain in working order a sparkarrester before using equipment onforest-covered, grass-covered, brush-coveredunimproved land. The state of Californiarequires this (Section 4442 of the CaliforniaPublic Resources Code). Other states mayhave similar laws. Federal laws apply onfederal land.

WARNING

Rotating parts can contact or entangle hands,feet, hair, clothing, or accessories.

Traumatic amputation or severe laceration canresult.

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 becomecaught.

When starting engine, pull cord slowly untilresistance is felt, then pull rapidly.

Direct coupled equipment components suchas, but not limited to, blades, impellors,pulleys, sprockets, etc., must be securelyattached.

Rapid retraction of starter cord (kickback) willpull hand and arm toward engine faster thanyou can let go.Broken bones, fractures, bruises or sprainscould result.

WARNING

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BRIGGS & STRATTON MODEL NUMBERING SYSTEM

3435367877797:7475769897999:9;9