Yamaha F50 Service Manual

							62Y3A113-16
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4. Check that the TDC “T” mark a
 on the
flywheel magnet is aligned with the mag-
net base pointer b
.
Power trim and tilt unit3
Checking the power trim and tilt 
operation
1. Fully tilt the outboard up and down a few
times and check the entire trim and tilt
range for smooth operation. Check the
power trim and tilt fluid level if necessary.
NOTE:
Be sure to listen to the winding sound of the
PTT motor for smooth operation.
2. Fully tilt the outboard up, and then sup-
port it with the tilt stop lever 1
 to check
the lock mechanism of the lever.
Checking the power trim and tilt fluid 
level
1. Fully tilt the outboard up, and then sup-
port it with the tilt stop lever 1
.
 WARNING
After tilting up the outboard, be sure to
support it with the tilt stop lever.
Otherwise, the outboard could suddenly
lower if the power trim and tilt unit should
lose fluid pressure.
2. Remove the tilt pin 2
. Ignition timing: BTDC 5 ±
 3° 
Control system / Power trim and tilt unit 
						

							CHK 
ADJ
Periodic checks and adjustments
3-1762Y3A11
3. Remove the reservoir cap 3
, and then
check the fluid level in the reservoir.
NOTE:
The fluid level should be at the brim of the
filler hole.
4. If necessary, add sufficient fluid of the
recommended type to the correct level.
5. Install the reservoir cap, and then tighten
it to the specified torque.
6. Install the tilt pin to its original position.
Lower unit3
Checking the gear oil level
1. Fully tilt the outboard down.
2. Remove the check screw 1
, and then
check the gear oil level in the lower case.
NOTE:
The gear oil level should be at the brim of the
check hole.
3. If necessary, add sufficient gear oil of the
recommended type to the correct level.
4. Install the check screw, and then tighten
it to the specified torque.
Replacing the gear oil
1. Fully tilt the outboard up, and then sup-
port it with the tilt stop lever 1
.
2. Remove the tilt pin 2
, and then install it
in the upper tilt pin hole a
.
3. Release the tilt stop lever and tilt the out-
board down until it contacts the tilt pin. Recommended power trim and tilt fluid:
ATF Dexron II
 
Reservoir cap: 8 N·m (0.8 kgf·m, 5.8 ft·lb)
S62Y3520
1
Recommended gear oil:
GEAR CASE LUBE (USA) or Hypoid 
gear oil
SAE: 90
Check screw: 7 N·m (0.7 kgf·m, 5.1 ft·lb) 
						

							62Y3A113-18
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4. Place a drain pan under the drain screw
3
, remove the drain screw, then the
check screw 4
 to drain the oil.
5. Check the oil for metal, discoloration, and
viscosity. Check the internal parts of the
lower case if necessary.
6. Insert the gear oil tube or gear oil pump
into the drain hole and slowly fill the gear
oil until oil flows out of the check hole and
no air bubbles are visible.
7. Install the check screw, quickly install the
drain screw, and then tighten them to the
specified torque.
Recommended gear oil:
GEAR CASE LUBE (USA) or Hypoid 
gear oil
SAE: 90
Oil quantity:
F50/F50A:
0.43 L (0.45 US qt, 0.38 Imp qt)
T50/FT50B, FT50C:
0.61 L (0.64 US qt, 0.54 Imp qt)
Check and drain screw:
7 N·m (0.7 kgf·m, 5.1 ft·lb)
Power trim and tilt unit / Lower unit 
						

							CHK 
ADJ
Periodic checks and adjustments
3-1962Y3A11
Checking the lower unit 
(for air leakage)
1. Remove the check screw 1
, and then
install the special service tool.
ÈFor USA and Canada
ÉFor worldwide
2. Apply the specified pressure to check
whether the lower unit can hold it for at
least 10 seconds.
CAUTION:
Do not over pressurize the lower unit, oth-
erwise the oil seals may be damaged.
NOTE:
Cover the check hole with a rag when remov-
ing the pressure/vacuum tester from the
lower unit.
3. If pressure drops below specification,
check the drive shaft and propeller shaft
oil seals for damage.
Checking the propeller
1. Check the propeller blades and splines
for cracks, damage, or wear. Replace if
necessary.
General3
Checking the anodes
1. Check the anodes and trim tab for
scales, grease, or oil. Clean if necessary.
Pressure/vacuum tester: YB-35956-A
Leakage tester: 90890-06762
Lower unit holding pressure:
100 kPa (1.0 kgf/cm
2, 14 psi)
S62Y3585 
						

							62Y3A113-20
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ÈFT50C only
ÉEHD, ED models
ÊEHT, ET models
ËF50/F50A only
CAUTION:
Do not oil, grease, or paint the anodes,
otherwise they will be ineffective.
2. Replace the anodes and trim tab if
excessively eroded.
Checking the battery
1. Check the battery electrolyte level. If the
level is at or below the minimum level
mark a
, add distilled water until the level
is between the maximum and minimum
level marks.2. Check the specific gravity of the electro-
lyte. Fully charge the battery if out of
specification.
 WARNING
Battery electrolyte is dangerous; it con-
tains sulfuric acid which is poisonous and
highly caustic.
Always follow these preventive measures:
•Avoid bodily contact with electrolyte as
it can cause severe burns or permanent
eye injury.
•Wear protective eye gear when handling
or working near batteries.
Antidote (EXTERNAL):
•SKIN – Wash with water.
•EYES – Flush with water for 15 minutes
and get immediate medical attention.
Antidote (INTERNAL):
•Drink large quantities of water or milk
followed with milk of magnesia, beaten
egg, or vegetable oil. Get immediate
medical attention.
Batteries generate explosive, hydrogen
gas. Always follow these preventive mea-
sures:
•Charge batteries in a well-ventilated
area.
•Keep batteries away from fire, sparks or
open flames (e.g., welding equipment,
lighted cigarettes).
•DO NOT SMOKE when charging or han-
dling batteries.
KEEP BATTERIES AND ELECTROLYTE
OUT OF REACH OF CHILDREN.
S62Y3640
S62Y3650
Lower unit / General 
						

							CHK 
ADJ
Periodic checks and adjustments
3-2162Y3A11
NOTE:
Batteries vary per manufacturer. The pro-
cedures mentioned in this manual may not
always apply, therefore, consult the instruc-
tion manual of the battery.
Disconnect the negative lead first, then the
positive lead.
Lubrication
1. Apply water resistant grease to the areas
shown.
ÈF50/F50A, T50/FT50B
ÉFT50C
Electrolyte specific gravity:
1.280 at 20 °C (68 °F)
S62Y3720
A 
						

							62Y3A113-22
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NOTE:
Apply grease to the grease nipple until it
flows from the bushings a
.
2. Apply anti-corrosion grease to the areas
shown.
General 
						

							CHK 
ADJ
Periodic checks and adjustments
3-2362Y3A11
— MEMO — 
						

							62Y3A11
FUEL
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Fuel system
Special service tools ..................................................................................... 4-1
Hose routing ................................................................................................... 4-2
Fuel and blowby hoses .............................................................................. 4-2
Cooling water hose .................................................................................... 4-3
Fuel line .......................................................................................................... 4-5
Fuel filter and fuel pump ............................................................................... 4-7
Checking the fuel pump ............................................................................. 4-9
Disassembling the fuel pump .................................................................... 4-9
Checking the diaphragm and valves ....................................................... 4-10
Assembling the fuel pump ....................................................................... 4-10
Carburetor unit ............................................................................................. 4-11
Carburetor..................................................................................................... 4-17
Checking the carburetor .......................................................................... 4-19
Checking the Prime Start......................................................................... 4-20
Assembling the carburetor....................................................................... 4-20
Adjusting the throttle link rod ................................................................... 4-21
Adjusting the pilot screw .......................................................................... 4-22
Synchronizing the carburetors ................................................................. 4-23
Adjusting the dash-pot (acceleration pump) ............................................ 4-24 
						

							FUELFuel system
4-162Y3A11
Special service tools4
Pressure/vacuum tester
YB-35956-A
Inductive self-powered tachometer
YU-08036-B
Carburetor synchronizer
YU-08030
Vacuum/pressure pump gauge set
90890-06756Digital tachometer
90890-06760
Vacuum gauge
90890-03159
For USA and Canada
For worldwide