Yamaha F50 Service Manual

62Y3A113-6
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2. Place a drain pan under the drain hole,
and then remove the drain bolt 2
 and let
the oil drain completely.
3. Place a rag under the oil filter, and then
remove the filter.
NOTE:
Be sure to clean up any oil spills.
4. Apply a thin coat of the new engine oil to
the O-ring of the new oil filter.
5. Install the oil filter, and then tighten it to
the specified torque.6. Install the drain bolt, and then tighten it to
the specified torque.
7. Fill the specified engine oil into...

CHK 
ADJ
Periodic checks and adjustments
3-762Y3A11
8. Install the oil filler cap and dipstick, and
then start the engine and warm it up for 5
minutes.
9. Turn the engine off, and then check the
oil level and correct it if necessary.
Checking the timing belt
1. Remove the flywheel magnet cover.
2. While turning the flywheel magnet clock-
wise, check the interior a
 and the exte-
rior b
 of the timing belt for cracks,
damage, or wear. Replace if necessary.
CAUTION:
Do not turn the flywheel magnet...

62Y3A113-8
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ÈFor USA and Canada
ÉFor worldwide
CAUTION:
•Apply force in the direction of the
arrows shown, to prevent the flywheel
holder from slipping off easily.
•To prevent damage to the engine or
tools, screw in the flywheel puller set
bolts evenly and completely so that the
flywheel puller plate is parallel to the fly-
wheel magnet.
NOTE:
Apply force to the crankshaft end until the fly-
wheel magnet comes off the tapered portion
of the crankshaft.3. Disconnect the stator couplers 3...

CHK 
ADJ
Periodic checks and adjustments
3-962Y3A11
6. Check that the “1” mark a
 on the driven
sprocket is aligned with the “” mark b
on the cylinder head, and that the “”
mark c
 on the drive sprocket is aligned
with the “” mark d
 on the crankcase.
Align if necessary.
CAUTION:
Do not turn the sprockets counterclock-
wise, otherwise the valve system may be
damaged.
7. While pushing against the tensioner side
of the belt, install the new timing belt from
the drive sprocket side with its part num-
ber in...

62Y3A113-10
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13. Install the flywheel magnet and flywheel
magnet cover.
ÈFor USA and Canada
ÉFor worldwide
CAUTION:
Apply force in the direction of the arrows
shown, to prevent the flywheel holder
from slipping off easily.
NOTE:
Apply engine oil to the flywheel magnet nut
before installation.
Checking the valve clearance
1. Remove the flywheel magnet cover, and
then disconnect the high-tension cords
and blowby hose 1
.2. Remove the spark plugs, fuel pump 2
,
and cylinder head cover 3
....

CHK 
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Periodic checks and adjustments
3-1162Y3A11
5. Turn the flywheel clockwise and align the
“4” mark c
 on the driven sprocket with
the “” mark b
 on the cylinder head.
CAUTION:
Do not turn the flywheel counterclock-
wise, otherwise the valve system may be
damaged.
6. Check the intake valve clearance for cyl-
inders #3 and #4, and the exhaust valve
clearance for cylinders #2 and #4. Adjust
if out of specification.
NOTE:
Adjust the valve clearance when the engine
is cold.
7. Loosen the locknut 4
,...

62Y3A113-12
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2. Clean the electrodes 1
 with a spark plug
cleaner or wire brush. Replace the spark
plug if necessary.
3. Check the electrodes for erosion and
excessive carbon or other deposits, and
the gasket for damage. Replace the
spark plug if necessary.
4. Check the spark plug gap a
. Adjust if out
of specification.
5. Install the spark plug, tighten it finger
tight b
, then to the specified torque with
a spark plug wrench c
.
Checking the thermostat
1. Remove the cover 1
,...

CHK 
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Periodic checks and adjustments
3-1362Y3A11
4. Check the thermostat valve opening at
the specified water temperatures.
Replace if out of specification.
5. Install the thermostat, new gasket, ther-
mostat cover, and cover.
Checking the cooling water passage
1. Check the cooling water inlet cover 1
and cooling water inlet for clogs. Clean if
necessary.
2. Place the lower unit in water, and then
start the engine.3. Check for water flow at the cooling water
outlet. If there is no water flow, check...

62Y3A113-14
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3. Align the alignment mark b
 on the throt-
tle cam 1
 with the alignment mark c
 on
the shift bracket.
4. Adjust the position of the throttle cable
joint until its hole is aligned with the set
pin d
 on the throttle cam.
CAUTION:
The throttle cable joint must be screwed
in a minimum of 8.0 mm (0.31 in) e
.
5. Connect the cable joint, install the clip,
and then tighten the locknut.
6. Check the throttle cable for smooth oper-
ation and adjust the cable length, if nec-...

CHK 
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Periodic checks and adjustments
3-1562Y3A11
Checking the engine idle speed
1. Start the engine and warm it up for 5 min-
utes.
2. Attach the special service tool to high-
tension cord #1 1
, and then check the
engine idle speed. Adjust if out of specifi-
cation.
3. Turn the throttle stop screw 2
 in direc-
tion a
 or b
 until the specified engine
idle speed is obtained.
NOTE:
To increase the idle speed, turn the throttle
stop screw in direction a
.
To decrease the idle speed, turn the...