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.