MerCruiser 8.1S HO User Manual

© 2006 Mercury Marine 8.1S and 8.1S Horizon Inboard Models 90-864841062 1206
NOTE: The following applies to CE marked products only.
Declaration of Conformance – Mercury MerCruiser
This sterndrive or inboard engine when installed in accordance to Mercury
MerCruisers’ instructions complies with the requirements of the following directives
by meeting the associated standards, as amended:
Recreational Craft Directive 94/25/EC; 2003/44/EC
Applicable Requirement Standards Applied
Owner’s manual (A.2.5) ISO 10240
Openings in Hull, Deck and superstructure (A.3.4) ISO 9093‑1; ISO 9093‑2
Handling characteristics (A.4) ISO 8665
Inboard Engine (A.5.1.1) ISO 15584; ISO 10088; ISO 7840; ISO 10133
Fuel System (A.5.2) ISO 10088; ISO 7840; ISO 8469
Electrical System (A.5.3) ISO 10133; ISO 8846
Steering system (A.5.4)
Applicable portions of: ISO 10592, ISO 8848 and
ABYC P‑17
Exhaust emission requirements (B.2) ISO 8178
Owner’s manual (B.4) ISO 8665
Noise emission levels (C.1) ISO 14509
Ignition‑protected equipment (Annex II) ISO 8846; SAE J1171; SAE J1191; SAE J 2031
Mercury MerCruiser declares that our sterndrive or inboard engines without integral
exhaust, when installed in a recreational craft, in accordance with the manufacturers
supplied instructions, will meet the exhaust emissions requirements of the directive
mentioned above. This engine must not be put into service until the recreational craft
in which it is to be installed has been declared in conformity, if so required, with the
relevant provision of the directive.
Electromagnetic Compatibility Directive 89/336/EC, 92/31/EEC and 93/68/EEC
Generic emission standard EN 50081‑1
Generic immunity standard EN 50082‑1
Vehicles, boats and internal combustion engine
driven devices ‑ Radio disturbance characteristics
SAE J551 (CISPR 12)
Electrostatic discharge testing EN 61000‑6‑2; EN 61000‑4‑2; EN61000‑4‑3
The notified body responsible for surveillance of the quality system under Full Quality Assurance
Module H of Directive 2003/44/EC is:
Det Norske Veritas
Norway
Notified Body Number: 0575
This declaration is issued under the sole responsibility of Mercury Marine and Mercury MerCruiser.
Patrick C. Mackey
President ‑ Mercury Marine, Fond du Lac, WI USA

MerCruiser 8.1S HO Specifications

General

Engine Type	V8
Compression Ratio	9.4:1
Ignition System	Electronic
Displacement	8.1L (496 cid)
Horsepower	425 hp
Torque	500 lb-ft
Bore x Stroke	4.0 in x 4.0 in
Weight	1, 050 lbs
Cooling System	Closed cooling system
Alternator Output	65 Amp
Fuel Requirement	87 octane minimum

Summary

Section 1 - Warranty

Warranty Registration

Mercury MerCruiser Limited Warranty

Covers new Mercury MerCruiser products for defects in material and workmanship.

Limited Warranty Against Corrosion

Provides protection against corrosion for specific engine and sterndrive models.

California Emissions Limited Warranty

Warranty for emission control systems on California-certified engines.

Owner's Warranty Responsibilities

Section 2 - Getting to Know Your Power Package

Lanyard Stop Switch

Explains the function and importance of the safety lanyard stop switch.

Remote Controls (Non-DTS Models)

Remote Controls (DTS Models)

Audio Warning System

Engine Guardian Strategy

Section 3 - On The Water

Safe Boating Suggestions

Carbon Monoxide Poisoning Awareness

Warning about CO hazards and importance of proper ventilation.

Basic Boat Operation

Protecting People In The Water

Impact With Underwater Hazards

Getting Started: Break-In Period

Instructions for the initial 20-hour engine break-in for optimal performance.

Section 4 - Specifications

Fuel Requirements

Important guidelines on using the correct type and octane of gasoline.

Engine Oil

Section 5 - Maintenance

Owner/Operator Responsibilities

Maintenance Schedule

Routine and scheduled maintenance tasks for inboard models.

Engine Oil Maintenance

Flushing the Seawater System

Section 6 - Storage

Cold Weather or Extended Storage

Preparing Power Package for Storage

Steps for preparing the engine and fuel system for storage.

Engine and Fuel System Preparation

Detailed steps for preparing the engine and fuel system before storage.

Draining the Seawater System

Instructions for draining the seawater system to prevent freeze damage.

Section 7 - Troubleshooting

Diagnosing EFI Problems

Engine Guardian System

How the system monitors and protects the engine from damage.

Engine Will Not Start Or Is Hard To Start

Engine Runs Rough, Misses And/Or Backfires

Excessive Engine Temperature

Identifying causes and solutions for engine overheating.

Section 8 - Customer Assistance Information

Owner Service Assistance