Yamaha F75F - Troubleshooting the Power Unit

Outboard motor troubleshooting
4-8
Troubleshooting the power unit
Symptom 1: Engine does not crank.
Symptom 1: Engine will not start (engine cranks).
Symptom 2 Cause Checking steps
See
p
age
Starter motor does
not op
erate
Gear shift not in the N posi-
tion
Set the gear shift to the N position. 10-5
Blown fuse Check the fuse. 5-5
Main relay malfunction Check the main relay. 5-18
Engine start switch mal-
function
Check the engine start switch. 5-33
Neutral switch malfunction Check the neutral switch. —
Short, open, or loose con-
nection in starter motor cir-
cuit
Check the wire harness for continu-
ity.
A-9
A-11
Starter motor malfunction
Disassemble and check the starter
motor
.
5-35
Starter motor oper-
ates, but the engine
does not cr
ank
Stuck piston or crankshaft
Disassemble and check the power
unit.
7-46
Stuck drive shaft
Check the drive shaft bushing. 9-17
Disassemble and check the lower
unit.
8-10
Symptom 2 Cause Checking steps
See
p
age
Engine ECM does
not op
erate
Blown fuse Check the fuse. 5-5
Short, open, or loose con-
nection in the engine ECM
ci
rcuit
Check for wire harness continuity
betw
een the main relay and the
engine ECM.
5-18
Check for continuity between the
engin
e ECM and ground.
5-18
Spark plug does not
produce a spar
k (all
cylinders)
Pulser coil malfunction
Measure the pulser coil output peak
vo
ltage.
5-29
Checking the pulser coil air gap. 7-2
Measure the pulser coil resistance. 5-29
Short, open, or loose con-
nection in the pulser coil
ci
rcuit
Check for wire harness continuity
betw
een the pulser coil and the
engine ECM.
A-8
A-10