Briggs & Stratton Vanguard 10V300 Operating instructions

10V300/12V300 Repair Manual
381584EN (Revision A)
BRIGGS&STRAT TON, LLC
CUSTOMER EDUCATION
Milwaukee, WI 53201 USA
Copyright ©2020. All rights reserved.
VANGUARDPOWER.COM
Vanguard®Single Cylinder OHV
Air Cooled Engine Repair
10V300/12V300
REPAIR MANUAL
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Foreword
This manual was written to assist engine technicians and service personnel with the maintenance and
repair procedures for Briggs & Stratton® engines. It assumes that persons using this manual have been
properly trained and are familiar with the service procedures for these products, including the proper use
of required tools 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 maintenance, troubleshooting, and repair procedures described in this manual are
appropriate for the Briggs & Stratton engines described herein. Alternative methods or procedures may
pose risks to both personal safety and engine reliability 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, LLC 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. However, neither publication is a substitute for a recognized training program for
engine technicians.
• For consumers, Small Engine and Equipment Maintenance Guide (Part No. CE8155) 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 (Part No. CE8020).
Both publications can be purchased at BRIGGSandSTRATTON.COM or through a local Briggs & Stratton
Authorized Service Dealer.
Copyright © 2020 Briggs & Stratton, LLC.
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, LLC.
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This engine repair manual includes the following engine models:
• MODEL 10V300
• MODEL 12V300
NOTE: Some models have limited service parts. Review the Illustrated
Parts List for part availability before conducting any service work.
NOTE: The images in this document are representative and may differ according to model.
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HOW TO USE THIS MANUAL
Besides describing the service maintenance tasks and the intervals at which they are to be performed,
two basic levels of service are presented in this manual: engine top end service and engine bottom end
service. The manner in which these instructions are used depends upon the tasks to be performed and
the level of disassembly required.
Remove External Assemblies
To prepare the engine for service, whether top or bottom end, first seeSECTION 4 - REMOVE
EXTERNAL ASSEMBLIESto remove the air cleaner, fuel tank, carburetor, etc. The order in which the
topics are presented is the order in which the assemblies are most easily removed from the engine.
NOTE: A few exceptions to this rule do exist, such as the muffler and rewind starter, which may be
serviced without having to remove other external assemblies.
Top End Service
If servicing only cylinder head components, seeSECTION 5 - DISASSEMBLE ENGINE, TOP END
DISASSEMBLY,and then proceed toSECTION 6 - SERVICE ENGINE SUBASSEMBLIES, CYLINDER
HEAD.When cylinder head service is complete, seeSECTION 7 - ASSEMBLE ENGINE, TOP END
ASSEMBLY.
Bottom End Service
If servicing bottom end components, such as the piston, connecting rod, crankshaft, etc., first
seeSECTION 5 - DISASSEMBLE ENGINE, TOP END DISASSEMBLY,and then proceed toBOTTOM
END DISASSEMBLYin the same section. When finished, move toSECTION 6 - SERVICE ENGINE
SUBASSEMBLIES,and seePISTON AND CONNECTING ROD; FLYWHEEL, CRANKSHAFT AND
CAMSHAFT;andCRANKCASE AND CRANKCASE COVER,for all service instructions. When bottom
end service is complete, seeSECTION 7 - ASSEMBLE ENGINE, BOTTOM END ASSEMBLY,and then
proceed toTOP END ASSEMBLYin the same section.
Install External Assemblies
When the top and bottom ends of the engine are assembled, seeSECTION 8 - INSTALL EXTERNAL
ASSEMBLIESto complete the project. The order in which the topics are presented is the order in which
the assemblies are most easily installed on the engine. These instructions also include any cleaning,
inspection, or adjustments that may be recommended.
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SECTION 1 – SAFETY AND GENERAL INFORMATION 1
SECTION 2 – MAINTENANCE 2
SECTION 3 – TROUBLESHOOTING/SPECIAL TOOLS 3
SECTION 4 – REMOVE EXTERNAL ASSEMBLIES 4
SECTION 5 – DISASSEMBLE ENGINE 5
SECTION 6 – SERVICE ENGINE SUBASSEMBLIES 6
SECTION 7 – ASSEMBLE ENGINE 7
SECTION 8 – INSTALL EXTERNAL ASSEMBLIES 8
SECTION 9 – SPECIFICATIONS 9
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1
3
SECTION 1 – SAFETY AND GENERAL INFORMATION
SAFETY ------------------------------------------------------------------------------------------------------------------------------------------------ 4
Safety Alert Symbol and Signal Words ---------------------------------------------------------------------------------------------------4
Hazard Symbols and Meanings ------------------------------------------------------------------------------------------------------------ 4
General Safety Messages --------------------------------------------------------------------------------------------------------------------4
GENERAL INFORMATION ------------------------------------------------------------------------------------------------------------------------7
Engine Identification --------------------------------------------------------------------------------------------------------------------------- 7
Fuel Recommendations -----------------------------------------------------------------------------------------------------------------------7
High Altitude ------------------------------------------------------------------------------------------------------------------------------------- 7
Oil Recommendations ------------------------------------------------------------------------------------------------------------------------- 7
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1
4
SAFETY
This manual contains safety information that will:
• Make you aware of hazards associated with engines.
• Inform you of the risk of injury associated with those
hazards.
• Instruct you how to avoid or reduce the risk of injury.
Safety Alert Symbol and Signal Words
The safety alert symbol identifies 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 information considered important but
not hazard-related.
Hazard Symbols and Meanings
Symbol Meaning Symbol Meaning
Safety information
about hazards that
can result in personal
injury.
Read and understand
the Operator's Manual
before operating or
servicing the unit.
Fire hazard Explosion hazard
Shock hazard Explosion hazard
Hot surface hazard Toxic fume hazard
Amputation hazard -
moving parts
Chemical hazard
Kickback hazard Thrown object hazard -
wear eye protection
Amputation hazard -
entanglement
General Safety Messages
Prior to work, read and understand the section(s) of this
manual that pertain to the job. Follow all safety warnings.
• Always use fresh gasoline. Stale fuel can cause gum
deposits in the carburetor and cause leakage, flow
restrictions, or other problems.
• Check fuel lines and fittings frequently for cracks or
leaks and replace if necessary.
WARNING
Before attempting to service this equipment, read and
understand this manual and the operating instructions
of the engine and the equipment.
WARNING
Failure to follow instructions could result in serious
injury (including paralysis) and even death.
WARNING
Battery post, terminals, and related accessories contain
lead and lead compounds - chemicals known to the
State of California to cause cancer and reproductive
harm. Wash hands after handling.
WARNING
Certain components in this product and its related
accessories contain chemicals known to the State
of California to cause cancer, birth defects, or other
reproductive harm. Wash hands after handling.
WARNING
Briggs & Stratton Engines are not designed for and are
not to be used to power: fun-karts; go-karts; children's,
recreational, or sport all-terrain vehicles (ATVs);
motorbikes; hovercraft; aircraft products; or vehicles
used in competitive events not sanctioned by Briggs
& Stratton. For information about competitive racing
products, see www.briggsracing.com. For use with
utility and side-by-side ATVs, please contact Briggs &
Stratton Power Application Center, 1-866-927-3349.
Improper engine application may result in serious injury
or death.
WARNING
The engine exhaust from this product contains
chemicals known to the State of California to cause
cancer, birth defects, or other reproductive harm.
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