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
Tilt Circuit - Down
When the down circuit is activated, the electric motor rotates in the opposite direction. As the pump’s gears rotate, fluid is
drawn through a check valve and into the pump’s inlet. The pump flow passes through a check valve and to the top of the tilt
cylinder. The fluid pushes the cylinder piston down and lowers the engine. Oil, from the bottom side of the cylinder, returns to
the inlet side of the pump. As the tilt cylinder retracts to its limit, down pressure is limited by an orifice in the down pressure
circuit.
Trail Over System
Should the outboard motor strike a submerged object while in forward motion, hydraulic pressure on the top side of the cylinder
will increase to cause the impact relief valve in the tilt cylinder to open. This allows the lower unit to trail over the obstruction.
The fluid in the top side of the cylinder opens the impact relief valve and flows into the cavity between the memory piston and
the cylinder piston. When the lower unit clears the submerged object, the thrust of the engine forces the engine back down. As
the cylinder piston is lowered, fluid trapped between the memory piston and the cylinder piston escapes through a return check
valve. Fluid below the memory piston is trapped in place, therefore, stopping the cylinder piston and returning the outboard to
its previous tilt position.
Power Tilt Features and Operation
Power Tilt
Models equipped with power tilt allow the operator to use the tilt switch to adjust the tilt position of the outboard from full down
to full up. This tilt system is designed to be adjusted when the engine speed is at idle speed or with the engine turned off. At low
idle speed, the outboard can be tilted up to permit shallow water operation.
a - Remote control tilt switch
b - Panel mount tilt switch
c - Tiller handle tilt switch
d - Cowl‑mounted tilt switch
Manual Tilt Release
If the outboard cannot be tilted using the power tilt switch, the outboard can be manually tilted.
NOTE: The manual tilt release valve must be tightened before operating the outboard to prevent the outboard from tilting up
during reverse operation.
Turn out the manual tilt release valve three turns counterclockwise. This allows manual tilting of the outboard. Tilt the outboard
to the desired position and tighten the manual tilt release valve.
31967
Tilt‑in Stop Adjustment
NOTE: The outboard should be positioned against the tilt‑in stop pins during operation.
DN
UP
UP
DN
UP
DN
DN
UP
a
b
c
d
DN
UP
32174
Power Tilt
90-8M0125265 eng NOVEMBER 2017 © 2018 Mercury Marine Page 5B-7