Product Manual
Table Of Contents
- Notice to Users of This Manual
- Precautions
- Replacement Parts
- Cleanliness and Care of Product
- Copyright and Trademark Information
- Manual Outline
- Section 1A - Specifications
- Table of Contents
- Model Specifications
- Ignition Specifications at 20 °C (68 °F)
- Charging and Starting Specifications
- Fuel System Specifications
- Cylinder Block/Crankcase Specifications
- Piston Specifications
- Cylinder Head Specifications
- Oil System Specifications
- Cooling System Specifications
- Power Tilt Specifications
- Gearcase Specifications
- Section 1B - Maintenance
- Table of Contents
- Cleaning Care
- Inspection and Maintenance Schedule
- Battery Inspection
- Flushing the Cooling System
- Fuel System
- Fuse Replacement - Electric Start Models
- Spark Plug Inspection and Replacement
- Timing Belt Inspection
- Engine Oil
- Corrosion Control Anodes
- Propeller Replacement
- Gearcase Lubrication
- Lubrication Points
- Storage Preparation
- Section 1C - General Information
- Table of Contents
- Recording Serial Number
- Model Year Production Code
- Engine Component Identification - Manual Start Model
- Engine Component Identification - Electric Start Model
- Following Complete Submersion
- Fuel Requirements
- Painting Procedures
- Emissions
- Shipping of Hazardous Material (HazMat) and Engine/Components Containing Hazardous Material
- Section 1D - Outboard Installation
- Section 1E - General Troubleshooting
- Table of Contents
- Conditions Affecting Performance
- Compression Check
- Cylinder Leakage Test
- Guardian Protection System
- Warning System
- Troubleshooting without a Computer Diagnostic System (CDS)
- Troubleshooting with CDS G3
- Accessing ECM Information with CDS G3
- CDS G3 Screens (10/15/20 EFI)
- Engine Control Module Pinout
- Fault Codes
- Section 2A - Ignition
- Table of Contents
- Ignition Specifications at 20 °C (68 °F)
- Ignition Theory of Operation
- General Troubleshooting
- Engine Control Module (ECM)
- Wire Color Code Abbreviations
- Sensors
- Ignition Components
- Section 2B - Charging and Starting Systems
- Section 3A - Fuel System Operation
- Section 3B - Troubleshooting and Diagnostics
- Section 3C - Service Procedures
- Section 4A - Cylinder Block/Crankcase
- Table of Contents
- Cylinder Block/Crankcase Specifications
- Piston Specifications
- Cylinder Block and Crankcase Components
- Crankshaft Components
- Powerhead Removal
- Cylinder Block Disassembly
- Powerhead Cleaning, Inspection, and Repair
- Powerhead Assembly
- Powerhead Installation
- Section 4B - Cylinder Head
- Section 4C - Oil Pump
- Section 4D - Cooling System
- Section 5A - Clamp/Swivel Bracket and Driveshaft Housing
- Table of Contents
- Clamp Bracket Components (Power Tilt)
- Clamp Bracket Components (Manual Tilt)
- Steering Arm and Copilot Components
- Driveshaft Housing Components
- Driveshaft Housing Cover Components
- Driveshaft Housing Covers
- Front Cowl
- Idle Exhaust Port Cover
- Powerhead/Midsection Assembly Separation
- Engine Mount Replacement
- Clamp Brackets, Swivel Bracket - Power Tilt Models
- Clamp Brackets, Swivel Bracket - Manual Tilt Models
- Driveshaft Housing Removal
- Driveshaft Housing Installation
- Shift Operation
- Kicker Strap (Tiller Handle Model)
- Section 5B - Power Tilt
- Table of Contents
- Power Tilt Specifications
- General Troubleshooting
- Power Tilt - General Information
- Power Tilt Components
- Theory of Operation
- Power Tilt Features and Operation
- Check Fluid and Purge the Power Tilt System
- Cowl-Mounted Tilt Switch
- Troubleshooting the Power Tilt System
- Power Tilt Removal
- Manual Release Valve Removal and Repair
- Power Tilt Motor
- Power Tilt Pump
- Power Tilt Installation
- Section 6A - Gear Housing (2.15:1)
- Table of Contents
- Gearcase Specifications
- Gear Housing and Driveshaft
- Propeller Shaft
- General Service Recommendations
- Draining and Inspecting Gear Housing Lubricant
- Gear Housing Removal
- Gear Housing Disassembly
- Gear Housing Assembly
- Pinion Bearing Installation
- Forward Gear Bearing Installation
- Bearing Carrier Assembly
- Water Pump Base Assembly
- Propeller Shaft Assembly
- Pinion Gear and Driveshaft Installation
- Forward Gear Backlash
- Shift Shaft and Water Pump Base Installation
- Water Pump Cover Assembly
- Propeller Shaft and Bearing Carrier Installation
- Gear Housing Installation
- Propeller Installation
- Section 7A - Throttle and Shift Linkage
- Section 7B - Tiller Handle
- Section 8A - Recoil Starter
- Section 9A - Color Diagrams
Cleaning and Inspection
Camshaft
1.
Measure the cam lobe at its maximum valve lift. Replace the cam if any of the cam lobe dimensions are out of
specification.
21391
Cam Lobe
Intake 23.63 mm (0.9303 in.)
Exhaust 23.80 mm (0.9370 in.)
2. Measure the outer diameter of the upper and lower bearing journals. Replace the cam if the journal dimensions are out of
specification.
a - Lower bearing outside diameter
b - Upper bearing outside diameter
Cam Bearing Journal
Lower bearing outside diameter 15.95–15.97 mm (0.628–0.629 in.)
Upper bearing outside diameter 17.95–17.98 mm (0.707–0.708 in.)
Valves
1.
Inspect the valves for damage or warpage. Replace if necessary.
a. Measure the valve stem cylindricity. Replace the valves if out of specification.
20970
Cylindricity (Maximum)
Intake and exhaust 0.01 mm (0.0004 in.)
2. Measure the valve stem outer diameter. Replace valves if out of specification.
20971
a
3004
b
Cylinder Head
90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 4B-15