Yamaha 20C Manuel D'utilisation page 146

Trouble
C. Warning buzzer
sounds or
indicator lamp
lights.
D. Engine power loss.
Possible Cause
1. Cooling system clogged.
2. Heat range of spark plug incorrect.
3. Specified engine oil not used.
4. Load on boat improperly distributed.
5. Water pump/thermostat faulty.
1. Propeller damaged.
2. Propeller pitch or diameter incorrect.
3. Trim angle incorrect.
4. Motor mounted at incorrect height
on transom.
5. Warning system activated.
6. Boat bottom fouled with marine
growth.
7. Spark plug(s) fouled or incorrect
type.
8. Weeds or other foreign matter
tangled on gear housing.
9. Fuel system obstructed.
10. Fuel filter clogged.
11. Fuel contaminated or stale.
12. Spark plug gap incorrect.
13. Poor connections or damaged
ignition wiring.
14. Failed ignition parts.
15. Specified engine oil not used.
16. Thermostat faulty or clogged.
17. Air vent screw closed.
18. Fuel pump damaged.
19. Fuel joint connection incorrect.
20. Heat range of spark plug incorrect.
1. Check water intake for restriction.
2. Inspect spark plug and replace it
with recommended type.
3. Check and replace oil with
specified type.
4. Distribute load to place boat on an
even plane.
5. Have serviced by a Yamaha
dealer.
1. Have propeller repaired or
replaced.
2. Install correct propeller to operate
outboard at its recommended
speed (r/min) range.
3. Adjust trim angle to achieve most
efficient operation.
4. Have motor adjusted to proper
transom height.
5. Find and correct cause of warning.
6. Clean boat bottom.
7. Inspect spark plug(s). Clean or
replace with recommended type.
8. Remove foreign matter and clean
lower unit.
9. Check for pinched or kinked fuel
line or other obstructions in fuel
system.
10. Clean or replace filter.
11. Fill tank with clean, fresh fuel.
12. Inspect and adjust as specified.
13. Check wires for wear or breaks.
Tighten all loose connections.
Replace worn or broken wires.
14. Have serviced by a Yamaha
dealer.
15. Check and replace oil with
specified type.
16. Have serviced by a Yamaha
dealer.
17. Open the air vent screw.
18. Have serviced by a Yamaha
dealer.
19. Connect correctly.
20. Inspect spark plug and replace it
with recommended type.
5-3
GB
Remedy