Trouble Recovery
90
Trouble
Engine power loss.
Item
Question
Answer
Propeller
Is propeller damaged?
Have propeller repaired or replaced.
Is propeller pitch or diameter incor-
rect?
Install correct propeller to operate
outboard motor at its recommended
speed (r/min) range.
Mounting height
Is outboard motor mounted at incor-
rect height on transom?
Have outboard motor adjusted to
proper transom height.
Alert system
Has alert system activated?
Find and correct cause of alert.
Boat bottom
Is boat bottom fouled with marine
growth?
Clean boat bottom.
Spark plugs
Are spark plugs fouled or of incorrect
type?
Inspect spark plugs. Clean or replace
with recommended type.
Is spark plug gap incorrect?
Replace spark plug.
Is heat range of spark plugs incor-
rect?
Inspect spark plugs and replace with
recommended type.
Lower unit
Are weeds or other foreign material
tangled on gear housing?
Remove foreign material and clean
lower unit.
Fuel system
Is fuel system clogged?
Inspect for pinched or kinked fuel line
or other obstructions in fuel system.
Fuel filter
Is fuel filter clogged?
Clean or replace fuel filter.
Fuel
Is fuel contaminated or stale?
Fill tank with clean, fresh fuel.
Is specified fuel not being used?
Replace fuel with specified type.
Ignition wiring
Is ignition wiring damaged or poorly
connected?
Inspect wires for breaks and wear.
Have connections tightened and bro-
ken or worn wires replaced by a
Yamaha dealer.
Electrical parts
Are electrical parts malfunctioning?
Have serviced by a Yamaha dealer.
Engine oil
Is specified engine oil not being
used?
Replace engine oil with specified ty-
pe.
Thermostat
Is thermostat clogged or malfunc-
tioning?
Have serviced by a Yamaha dealer.
Fuel tank
Is fuel tank air vent restricted or
clogged?
Remove obstruction.
Fuel pump
Is fuel pump malfunctioning?
Have serviced by a Yamaha dealer.
Fuel joint
Is fuel joint connection incorrect?
Connect correctly.
Control lever
Is engine not responding properly to
control lever position?
Have serviced by a Yamaha dealer.
Trouble
Engine vibrates excessively.
Item
Question
Answer
Propeller
Is propeller damaged?
Have propeller repaired or replaced.
Are weeds or other foreign material
tangled on propeller?
Remove and clean propeller.
U6KNK0E0.book Page 90 Monday, November 7, 2022 10:23 AM