Engine Maintenance

Engine Maintenance Chapter 10 Emergency Repairs Afloat

Objectives for the Student • Have knowledge of some basic troubleshooting techniques for the fuel, cooling, and ignition systems of gasoline engines • Have knowledge of basic troubleshooting techniques for the fuel and cooling systems of diesel engines • Have knowledge of some simple repairs that can be made while afloat that will aid in getting the boat back to a safe harbor

Emergency Repairs Afloat • If the Engine Stops • do not panic • the trouble is usually something simple • Assess the Situation • safety is paramount concern • when the boat is safe, turn to the engine problem

Emergency Repairs Afloat • Carry a small tool kit for emergency repairs • Carry spare parts • Impellers • Belts

Emergency Repairs Afloat • Did it Sputter-Run-Sputter-Run-Quit? • Did it Gradually Lose Power? • Did it Stop Instantaneously?

Emergency Repairs Afloat • Knowing Symptoms Can Assist in: • determining the cause of common problems • helping you suggest realistic repairs to a mechanic

Gasoline Inboard Engines • Gasoline is Highly Inflammable • it is always a fire hazard • it requires constant care and close attention

Gasoline Inboard Engines • Fuel System • indications • engine sputters and stops • is fuel available to the engine? • determine if fuel is reaching the manifold • engines with carburetors • remove flame arrestor and look down into carburetor • engines with fuel injectors • these systems require specialized test equipment and repair is beyond the scope of this course

Gasoline Inboard Engines • Troubleshooting the Fuel System • check the fuel pump • are there signs of leakage? • remove the oil dip stick and sniff for gasoline • check the fuel filters • is the filter clogged? • is there water in the filter? • check for water in the fuel supply

Emergency Repairs Afloat • Cooling System • indications • engine gradually loses power and stops and temperature gauge reads hot • check the drive belt • if broken, only remedy is a new belt • Nylon belt may substitute • sometimes, re-tensioning may work

Emergency Repairs Afloat • Cooling System • a hot engine will usually restart after it has cooled down • check to see if cooling water is exiting the exhaust • if not, the raw water pump has failed or the intake is blocked • if yes, either the thermostat or circulating pump has failed

Emergency Repairs Afloat • Troubleshooting the Cooling System • thermostat failure • solution: temporarily remove thermostat • if gasket is damaged, fashion one from cardboard • circulating pump failure • indicator is leakage around shaft • may work sufficiently at low speed • seawater pump failure • first, check for blockage • remedy for failed pump: new impeller

Emergency Repairs Afloat • 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

Ignition System • If engine stops suddenly, problem is probably the ignition system • inspect distributor for cracks, corrosion, burning • check coil wire for looseness • inspect breaker points for pitting, corrosion, burning • replace condenser if points are pitted or blackened

Ignition System • Spark Plugs • inspect plug wires for looseness • inspect for cracked porcelain, burned electrodes, excessive electrode gap

Gasoline Outboard Engines • Fuel System Problems • rust in portable tanks – solution: replace tanks • infrequent use, gas left in carburetor – requires mechanic • if the engine sputters and quits, check the tank • is there fuel in the tank? • is the vent valve open?

Gasoline Outboard Engines • Fuel System Problems • fuel lines • check for cracks that can admit air • squeeze the priming bulb to make sure there is fuel in the line and carburetor • water in fuel • check the filter for water • change to a spare tank

Gasoline Outboard Engines • Cooling System Problems • check the cooling water overflow vent • is water coming out? • if not: • shut down the engine • check for intake blockage • if no water and intake is not blocked • impeller has failed • replace the impeller

Gasoline Outboard Engines • Ignition System Problems • if the engine stops instantaneously, ignition system is suspect • check for loose wires throughout • check for high voltage at spark plug leads • Remove one plug wire and hold about ¼” from block, then crank the engine • Spark should jump from wire to metal • If no spark, call a mechanic • Four stroke outboards should be treated the same as gasoline inboards

Diesel Engine • Fuel System Problems • greatest problem with diesels • usually clogged filters • change/clean/drain filters • air trapped in system will keep engine from operating • bleed air from the system when filters are changed • bacteria can grow in diesel fuel • fuel tank must be purged and cleaned

Troubleshooting Summary • If the Engine Stops • do not panic • the trouble is usually something simple • safety is paramount concern

Troubleshooting Summary • Remember How the Engine Sounded • did it sputter-run-sputter-run-quit? • likely a fuel system problem • did it gradually lose power? • likely a cooling system problem • did it stop instantaneously? • likely an ignition system problem

Troubleshooting Summary • 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

General Troubleshooting Methodology • Check the Obvious • Check the Easy • Check Systematically • Make No Erratic Adjustments

Remember… You should be able to identify problems and explain them to a mechanic

Engine Maintenance