Troubleshooting The Lower Unit - Yamaha F150A Service Manual

Symptom 1: PTT unit does not hold the outboard motor up.
Symptom 2
PTT fluid pressure does
not increase

Troubleshooting the lower unit

Troubleshooting consists of the following 3 items:
Symptom 1: Specific trouble conditions
Symptom 2: Trouble conditions of an area or individual part
Cause: Trouble causes of symptom 2
— : Not applicable
Symptom 1: Shift mechanism of the forward gear and reverse gear does not operate prop-
erly.
Symptom 2
—
—
Cause
Manual valve open
Insufficient PTT fluid
—
PTT fluid leakage
Clogged fluid passages
Cause
Shift cable is not adjusted
properly.
Shift rod does not operate
properly.
Shift mechanism malfunction
(in lower unit)
Outboard motor troubleshooting
Checking steps
Check the manual valve.
Add sufficient PTT fluid.
Check the hydraulic pressure.
Check the PTT fluid leakage.
Disassemble and check the PTT unit.
Check the valves for damage.
Check the fluid passages for obstruc-
tions.
Checking steps
Adjust the shift cable.
Check the shift rod for wear.
Check the detent mechanism.
Check the shift rod connection.
Check the dog clutch and related parts.
Check the forward gear, reverse gear,
and pinion for damage and wear.
4-17
See
page
0
9-60
10-14
9-35
10-14
1
9-41
9-48
9-54
9-41
2
9-54
2-19
3
4
5
See
page
6
3-9
8-11
8-17
7
9-1
8-27
8-13
8-16
8
8-22
8-22
9
10
A