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Comprehensive Guide to Removing a 1985 V4 Johnson 90 HP Lower Unit

Introduction

Outboard motor lower units play a crucial role in propulsion and steering. Regular maintenance and repairs are essential to ensure optimal performance and longevity. This comprehensive guide will provide a step-by-step procedure for removing the lower unit of a 1985 V4 Johnson 90 HP outboard motor.

Safety Precautions

Wear appropriate safety gear, including gloves and safety glasses.
Secure the outboard motor to prevent accidental movement.
Disconnect the battery to eliminate any electrical hazards.
Follow all instructions carefully and heed warnings.

Tools and Materials

Essentials:
- Socket wrench set
- Gear puller
- Mallet
- Flathead screwdriver
- Drain pan
- Rags
Recommended:
- Knee-pad
- Light
- Magnetic pick-up tool

Step-by-Step Procedure

1. Drain the Gearcase Oil

Place a drain pan underneath the lower unit.
Loosen the small drain plug on the bottom of the gearcase.
Allow the oil to drain completely into the pan.

2. Disconnect the Shift Linkage

Locate the shift linkage arm near the top of the lower unit.
Push the arm towards the engine until it disengages from the shift shaft.
Remove the cotter pin and clevis pin from the arm.

3. Loosen the Propeller Nut

Shift the outboard motor into forward gear.
Use a socket wrench to loosen the propeller nut. Do not remove it completely yet.

4. Remove the Propeller

Once the nut is loosened, hold the propeller with one hand and strike the back of the nut with a mallet using the other hand.
The propeller should pop off the shaft.

5. Remove the Gear Housing

Upper Portion:
- Use a socket wrench to remove the two bolts holding the upper gear housing to the engine.
Lower Portion:
- Remove the two bolts holding the lower gear housing to the upper housing.
Disconnect:
- Disconnect the speedometer cable from the gear housing, if applicable.

6. Separate the Gear Housing and Lower Unit

Use a gear puller to separate the gear housing from the lower unit.
Position the puller on the gear housing and secure it.
Tighten the bolt on the puller until the gear housing comes loose.

7. Remove the Lower Unit

Once the gear housing is separated, tilt the lower unit back and lift it off the drive shaft.
Be careful not to damage the gasket between the lower unit and the engine.

8. Inspect and Service

Inspect the gasket, shift rod, propeller shaft, and other components for wear or damage.
Replace any damaged parts as necessary.

Tips and Tricks

Use Knee-Pads: Kneeling for extended periods can be uncomfortable. Use knee-pads to protect your knees.
Light Up: Provide adequate lighting in the work area to see clearly.
Magnetic Pick-Up: Use a magnetic pick-up tool to retrieve bolts or other small objects that may drop into hard-to-reach areas.

FAQs

1. Can I remove the lower unit on my own?

Yes, you can remove the lower unit on your own with the proper tools and safety precautions.

2. How often should I service my lower unit?

1985 v4 johnson 90hp lower unit remove

Comprehensive Guide to Removing a 1985 V4 Johnson 90 HP Lower Unit

It is recommended to service the lower unit every 100 hours of operation or annually, whichever comes first.

3. How do I know if my lower unit needs repair?

Warning signs include excessive noise, vibration, difficulty shifting, or oil leaks.

Introduction

4. Can I reuse the gasket between the lower unit and the engine?

Essentials:

No, the gasket should always be replaced when removing and reinstalling the lower unit.

5. How much torque should I apply when tightening the propeller nut?

Tighten the propeller nut to the specifications provided in the Johnson service manual. Over-tightening can damage the threads.

6. What is the purpose of the shift linkage?

The shift linkage connects the gear shift lever to the shift rod, which moves the gears inside the gear housing to change gears.

Call to Action

Removing the lower unit of a 1985 V4 Johnson 90 HP outboard motor requires careful attention and proper procedures. By following the steps outlined in this comprehensive guide, you can complete the task effectively and safely. If you encounter any difficulties or prefer professional assistance, do not hesitate to consult with a qualified marine mechanic.