1. Chapter 13
Engines for Sailboats

2. Lesson Objectives Outboard engines for sailboats
Two stroke vs. 4 stroke
Engine maintenance/troubleshooting
Inboard engines
Diesel vs. gas
Diesel maintenance
Electrical systems
SSSpptChpt13EnginesforSailboats ppt

3. Outboard Characteristics
Outboard engine:
May be lifted out of the water when not in use
Readily removable for service and repair
Uses no cabin space
Newer engines are very reliable
SSSpptChpt13EnginesforSailboats ppt

4. 2 Stroke Versus 4 Stroke
2 stroke: crankshaft turns once per power stroke
4 stroke: turns twice per power stroke
2 stroke is lighter-more power per weight
2 stroke: lubricating oil is pre-mixed with gasoline and burns (white smoke)
2-stroke pollutes more than 4-stroke
SSSpptChpt13EnginesforSailboats ppt

5. 2 Stroke Vs. 4 Stroke
4 stroke: more expensive & heavier per horsepower
4 stroke: oil in sump & pumped thru engine
4 stroke more reliable, quieter, and more efficient
Less polluting
SSSpptChpt13EnginesforSailboats ppt

6. Outboard Maintenance Change lube oil as recommended Change spark plugs
Change lower unit oil
Don’t use old fuel
SSSpptChpt13EnginesforSailboats ppt

7. Inboard Engines Generally used in larger sailboats
Can be very quiet with low vibration
Requires additional safety precautions
Requires a transmission and stuffing box
Requires a cooling system
Open system-sea water circulates through engine and back to the sea
Closed system-sea water circulates through heat exchanger and back to sea
SSSpptChpt13EnginesforSailboats ppt

8. Stuffing Box
Allows propeller shaft to rotate while preventing water from leaking into boat
Cools itself if properly adjusted
Some types are drip-free
Wear out over time and need repacking
SSSpptChpt13EnginesforSailboats ppt

9. Diesel Engines More costly and heavier than gas
More reliable and fuel efficient
Less dangerous—diesel fuel is not explosive like gasoline
SSSpptChpt13EnginesforSailboats ppt

10. Diesel Maintenance Less maintenance than gas engines
No spark plugs, distributor, carburetor
Most problems are fuel-related contamination– dirty fuel and algae
Starter motor has heavier starting load
Good battery charging system & electrical connections
SSSpptChpt13EnginesforSailboats ppt

11. Batteries One for engine starting, one for accessories
Battery switch-“Off, 1, 2, Both”
Battery must be protected, secured & vented
Deep cycle battery allows repeated discharge
Clean battery connections are important
SSSpptChpt13EnginesforSailboats ppt

12. Battery Charging Long periods of being unused are hard on your battery
Under charging and over charging are equally bad
Float versus trickle charging
SSSpptChpt13EnginesforSailboats ppt

13. Shore Power 120V shore power grounding problems
Electrolysis can cause major problems
Nearby boats can cause damage
Portable testers are available
Consider GFI protection for on-board systems
SSSpptChpt13EnginesforSailboats ppt

14. Sailboat Propellers (with Inboards)
Propeller drag affects performance
Folding propeller is an option
SSSpptChpt13EnginesforSailboats ppt

15. Prop Walk Right hand props pull stern to port (slightly)
Prop walk is obvious when in reverse before the boat has a chance to gain sternway
More pronounced in full-keeled boats
Use a short burst of reverse power to pull stern to port when docking
SSSpptChpt13EnginesforSailboats ppt

16. Propeller Maintenance
Vibration usually indicates need for propeller and/or shaft repair
Guard against galvanic action
Sacrificial zincs prevent erosion of bronze propellers
Check annually
SSSpptChpt13EnginesforSailboats ppt

17. Tool Kit
An entire trip can be ruined for the lack of a simple tool or part
Carry spares for all expendable items and tools to change them
Fuel filters, drive belts, water pump impellers, oil filters, fuses, lamp bulbs, etc.
Common tools: wrenches, screwdrivers, pliers, sockets, various stainless steel screws, hose clamps, zip ties, etc. spray lubricants (WD40)
SSSpptChpt13EnginesforSailboats ppt