3 Inboard Spark Engines - Part 2 29 COURSE LESSON TITLE Chapter 3 Inboard Spark Engines Part 2 PRESENTATION TIME PRESENTATION METHOD MATERIALS REQUIRED 2 hours Participative Lecture Ch3 PPT slides, computer, projector Objectives Topics Resources & Notes GAIN ATTENTION Review homework from Chapter 2 Slide 1 OBJECTIVE PRESENTATION Routine Maintenance Upon completion of this chapter, the student should have: a good understanding of how to perform routine maintenance of the fuel, cooling, exhaust, lubrication, ignition, and electrical systems of the spark-ignition marine engine. knowledge of how to perform basic troubleshooting procedures to determine the source of problems when they occur. Routine Maintenance Consists of: reading and understanding maintenance and warranty documents doing the most obvious maintenance items checking oil and fuel levels inspecting fluids and batteries changing oil and filters keeping the engine and components clean Knowing Symptoms Can Assist in: Determining the cause of common engine problems Suggesting realistic repairs to a trained technician Gasoline is Highly Inflammable it is always a fire hazard it requires constant care and close attention Gasoline is Rated by Octane Number the higher the octane number the better the burn use only high quality gasoline beware of additives such as ethanol Fuel Must be Filtered filter must be placed ahead of the carburetor or injector inlet it is a good idea to include a water separator check regularly and replace often Slide 2 Slides 3 4 Slides 5 6 Slide 7
30 3 Inboard Spark Engines - Part 2 Objectives Topics Resources & Notes Cooling System Properly Maintained, it is Generally Trouble-Free Principal Maintenance Includes: maintaining circulating pumps in good operating condition preventing corrosion reducing the formation of scale in water jackets and heat exchangers preventing leaks in the system Slide 8 Lubrication System 1. Rotary Impeller Pump most frequently used raw water pump may be damaged by contaminants in raw water if not used for long periods, impellers become bent and lose efficiency should be changed at start of every boating season normally a job for a trained technician 2. Centrifugal Pump usually mounted on front of engine most are driven by a fan belt only adjustment is to check belt tension coolant leakage or loose shaft suggests failing pump normally a job for a trained technician 3. Corrosion Prevention erosion of the cooling system usually caused by galvanic action can be prevented by the use of sacrificial anodes (zincs) o inspect frequently o keep clean and replace when >50% disintegrated 4. Scale Formation indirect cooling system most affected gradual increase in heat exchanger temperature is indicative of excessive scale keep recommended fresh antifreeze and a fresh water supply It is Important to Maintain a Regular Lubrication Maintenance Schedule check engine oil before start of each engine operation check oil at every refueling change engine oil at regular intervals recommended oil changes every 100 hours of operation or every three months refill with correct amount and type of oil replace the oil filter at every oil change Slide 9 Slide 10 Slide 11 Zinc is a generic term for a sacrificial anode. Students may point out that other alloys are sometimes used they are correct. It depends on the application. Slide 12 Slide 13
3 Inboard Spark Engines - Part 2 31 Objectives Topics Resources & Notes Ignition System 1. Distributor Ignition System inspect distributor periodically for cracks, corrosion or burning inspect breaker points periodically for burning, pitting and corrosion replace condenser and points if they are corroded or blackened Slide 14 Electrical and Starting System Trouble Shooting 2. Solid State Ignition System little maintenance is required inspect coil periodically and keep it clean 3. Spark Plugs inspect for cracked porcelain, burned electrodes, correct electrode gap in proper operation, insulator will have light tan color burned plugs indicate severe operating conditions 1. Batteries most common cause of failure is owner neglect maintenance includes: o keeping terminals free of corrosion o ensuring cables are tight o cells are topped off with distilled water Discuss use of multimeter 2. Alternator no routine maintenance required check drive belt for proper tension o no more than ½ inch deflection per foot of span 3. Electrical Wiring and Fuses/Breakers periodically inspect all exposed wiring most starter problems are associated with weak battery or starter solenoid check condition of battery and connections 1. If the Engine Stops While Underway do not panic trouble is usually something simple remember: the safety of your boat is the primary concern 2. Remember How It Sounded When It Stopped did it sputter-run-sputter-run-quit? o most likely a fuel system problem did it gradually lose power? o most likely a cooling system problem did it stop instantaneously? o most likely an ignition system problem Slide 15 Slide 16 Slides 17 18 With the multimeter, set it to read DC voltage, and then test the battery in an opencircuit condition. Don t use the current setting, as this will blow the fuse in the device. Slide 19 Slide 20 Slide 21 Slide 22
32 3 Inboard Spark Engines - Part 2 Objectives Topics Resources & Notes 3. Best Advice: Check Before You Go fuel level is there enough to take you there and get you back? oil level battery water drive belt tension bilge water level Slide 23 4. Fuel System indications o engine sputters and stops check fuel level in the tank check tank vent and valves o have vents been inadvertently closed? 5. Carburetors operate the throttle a few times remove flame arrestor and look down into carburetor Never Operate the Engine Without the Flame Arrestor in Place! Check to See that Choke is Working Slide 24 Slide 25 6. Check for Oil in the Crankcase remove the dip stick and sniff for fuel 7. Check Fuel Filters remove filter and check for water in the element change if filter is clogged 8. Cooling System Problems indications o engine stops and temperature gauge reads hot check the drive belt on the water pump first o is it stretched or broken? o temporary belt can be made from a Nylon belt or ladies panty hose a hot engine will usually restart after it has cooled o after restarting, check for water exiting from the exhaust o if no water is exiting, check water pump for leaks o If no leaks, check the outdrive or inlet strainer for blockage o If water is flowing normally, check the thermostat Slide 26 Slides 27 28
3 Inboard Spark Engines - Part 2 33 Objectives Topics Resources & Notes 9. Ignition System Problems indications o engine stops abruptly check the coil wire (if your engine has a distributor ignition system) o is it loose at either distributor or coil end? o check distributor cap for cracks o check the rotor inside the distributor cap o check the points are they burned or pitted? check spark plug wires o make sure wires are tight at both distributor and spark plugs solid state ignition systems o normally have very few problems o require a trained technician for service Slides 29-30 EXERCISE SUMMARY HOMEWORK Answer homework questions for Chapter 3
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3 Inboard Spark Engines - Part 2 35 1. Gasoline as a fuel is rated by: a. grade. b. octane number. c. BTU. d. cetane number. Homework Questions 2. Fuel filters should be located: a. immediately behind the carburetor or injectors. b. as close to the oil lines as possible. c. immediately ahead of the carburetor or injection system. d. as close to the water pump as possible. 3. The principal maintenance requirements for the inboard cooling system involve: a. preventing leaks, maintaining pumps, reducing water volume, and reducing scale. b. reducing water volume, preventing corrosion, reducing scale, and maintaining pumps. c. preventing corrosion, reducing scale, maintaining pumps, and reducing water volume. d. preventing leaks, reducing scale, maintaining pumps, and preventing corrosion. 4. Impellers on rotary pumps as a minimum should be changed: a. every time the oil and filters are changed. b. at the start of every boating season. c. at the close of every boating season. d. every time the coolant is changed. 5. Zinc sacrificial anodes are employed in the cooling system to: a. counteract galvanic action in the cooling system parts. b. prevent overheating of the raw water supply. c. counteract stray current corrosion. d. prevent scale formation. 6. With an indirect cooling system a gradual increase in the fresh water temperature is an indication of: a. galvanic action. b. stray current corrosion. c. excessive scale formation. d. overheating of the raw water supply. 7. The most common schedule for changing engine oil and filters is every: a. 100 hours of operation or every three months. b. 100 hours of operation or every six months. c. 50 hours of operation or every three months. d. 50 hours of operation or every six months. 8. The most common cause of marine battery failure is: a. overfilling with water. b. neglect. c. over tightening cable clamps. d. failure to use proper tie-downs.
36 3 Inboard Spark Engines - Part 2 9. If the engine stops while under way, the first thing to remember is: a. the marine towing company s VHF calling channel. b. did you install the drain plug in the transom. c. do not panic. d. see if you have sufficient PFDs onboard. 10. An engine that coughs and sputters before stopping usually indicates a problem with the system. a. ignition b. lubrication c. fuel d. cooling 11. An engine that stops instantaneously usually indicates a problem with the system. a. cooling b. ignition c. lubrication d. fuel 12. One of the most common causes of engines running hot is: a. the thermostat failed completely open. b. the water pump belt stretched or broke. c. the oil reservoir was overfilled. d. insufficient anti-freeze was added to the coolant. 13. Most gasoline inboard engine problems are related to: a. transmissions, ignition, and cooling. b. cooling, transmissions, and fuel. c. fuel, ignition, and cooling. d. fuel, transmissions, and cooling. 14. The first indication of marine engine trouble is often a change in the: a. sound of the engine while running. b. steering control. c. ability to reverse gear. d. amount fuel consumed in a given time period. 15. An engine that gradually loses power and stops is usually an indication of a problem with the system. a. fuel b. lubrication c. cooling d. ignition
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