This service and repair manual covers the Volvo Penta AQ171 marine engine, a 2.3 L inline-4 cylinder engine featuring fuel injection and water-cooling. Known for its robust engineering and reliability, the AQ171 is designed for dependable performance in marine applications. This manual provides comprehensive information to ensure the optimal operation and longevity of your Volvo Penta AQ171 engine. The purpose of this manual is to offer detailed guidance for owners, mechanics, and technicians. It encompasses essential areas such as general maintenance, periodic lubrication, troubleshooting procedures, and in-depth engine and transmission service and repair. Furthermore, the manual includes information on the electrical system, wiring diagrams, chassis and body, emission system, engine control system, brake system, suspension, steering, axle components, and restraint systems, providing a complete resource for maintaining and repairing the AQ171.