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
6. To reface a valve seat, use a 30°, 45°, and 60° valve seat cutting tool.
a - 30° angle
b - 45° angle
c - 60° angle
NOTE: When twisting the cutter, keep an even downward pressure to prevent chatter marks.
NOTE: After refacing the valve seat or replacing the valve and valve guide, the valve seat and valve face should be
lapped.
7. Start with the 45° cutting tool to clean up any pitting or rough surface of the valve seat.
a - Rough surface of valve seat
8. Use the 30° cutting tool to adjust the contact width of the top edge of the valve seat.
a - Previous contact width
9. Use the 60° cutting tool to adjust the contact width of the bottom edge of the valve seat.
a - Previous contact width
10. If the valve seat contact area is too wide and situated in the center of the valve face, use the 30° cutting tool to cut the top
edge of the valve seat and the 60° cutting tool to cut the bottom edge of the valve seat, to adjust its contact width.
a - Previous contact width
20964
a
b
c
45°
a
20954
30°
a
20976
60°
a
20977
a
30
o
60
o
20979
Cylinder Head
Page 4B-18 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017