Preventive Maintenance and Troubleshooting

Chapter 12

Objectives

Know how to clean and engine. Check and change the oil in a four-cycle

engine. Mix fuel and oil correctly for a two-cycle

engine.

Objectives

Perform preventive maintenance on engine systems, including the crankcase breather, air cleaner, and muffler.

Prepare a water cooling system for storage. Describe systematic troubleshooting. Use manufacturer’s service manuals to

determine engine specifications and explain why this information is necessary when servicing a small engine.

Preventative maintenance

It is what it sounds like. List some tasks that would fall under the

heading of preventative maintenance.

Keeping Engines Clean

What if the cooling fins are not clean?

Methods of cleaning Compressed Air Scrape with a wooden block Aerosol Cleaner

Checking oil level and condition

Dipstick

Filler Plug

What happens if there is too much oil?

Checking oil level and condition

How do you know when to change oil?

Loaded oil:

Changing Oil

Warm the engine up first. Why?

The name of the game is to get all the old oil out and keep everything dirt free.

Oil filters:

Mixing oil and fuel

Some gas…then oil...shake…rest of gas…shake

Oil should remain suspended indefinitely. If fuel is stored for a few weeks or more,

gasoline stabilizer should be added to prevent oxidation, varnish, and corrosive acids.

Condensation

Why does it happen?

How can you prevent it?

Air Cleaner Service

Before each season, or more often in dusty conditions.

Follow manufacturer’s recommendation (especially if under warranty).

Oil-wetted

Dry types

Dual-element

Crankcase Breather Service

Muffler Service

Why might you need a new one?

NEVER CLEAN WITH GASOLINE!

Maintaining Water Cooling System

Rust Inhibitor:

Flushing (Reverse Flushing):

Should you run straight water?

Systems Cooled with Saltwater

Saltwater is extremely corrosive.

Gearbox should be removed from water when it is not running.

Fresh water should be run through the engine using a scoop or operating the engine in a barrel of fresh water.

Everything should be wiped clean with an oily rag.

Storing Water Cooled Engines

Antifreeze Rust Inhibitor

Drain Completely if the engine won’t be used all winter.

Drain gearcase of outboard engines and refill with the proper grease.

Follow manufacturer’s recommendations.

SYSTEMATIC TROUBLESHOOTING K.I.S.S. Check the easiest things first.

What does an engine need in order to run? - - - - - -

Checking RPM

Using the engine’s vibration

Optical Tachometer

Stoboscope

Test Compression

List the steps:

What should compression be?

What are we checking for?

Test Differential Pressure

Leak down test:

What are we checking?

How is it done?

Service Information

Look in the service manual.

Follow the recommended procedures. Most engines will be the same, but it is good to read about your engine b/c something may be a bit different.

Troubleshooting Charts

Very handy!

Tolerances, Clearances, Torque, and Sequence You MUST check them and they MUST be

right. Cutting corners will only hurt your

performance and your engine in the end.

Objectives

Know how to clean and engine. Check and change the oil in a four-cycle

engine. Mix fuel and oil correctly for a two-cycle

engine Perform preventive maintenance on engine

systems, including the crankcase breather, air cleaner, and muffler.

Objectives

Prepare a water cooling system for storage. Describe systematic troubleshooting. Use manufacturer’s service manuals to

determine engine specifications and explain why this information is necessary when servicing a small engine.