Yamaha Fz1n Service Manual

ENGINE
3-6
If the valve pad is marked “158”, the pad 
thickness is 1.58 mm (0.062in)
d. Calculate the sum of the values obtained in  steps (b) and (c) to determine the required 
valve pad thickness and the valve pad 
number.
Example:
1.58 mm (0.062 in) + 0.05 mm (0.002 in) = 
1.63 mm (0.064 in)
The valve pad number is 163.
e. Round off the valve pad number according  to the following table, and then select the 
suitable valve pad.
NOTE:
Refer to the following table for the available 
valve pads....

ENGINE
3-7
Refer to GENERAL CHASSIS on page 4-
1.
 Fuel tank Refer to FUEL TANK on page 7-1.
3. Remove:
 Synchronizing hoses “1”
4. Install:  Vacuum gauge “1”(onto the synchronizing hose)
 Digital tachometer
(near the spark plug)
5. Install:  Fuel tankRefer to FUEL TANK on page 7-1.
6. Start the engine and let it warm up for sev- eral minutes.
7. Check:
 Engine idling speedOut of specification  → Adjust.
Refer to ADJUSTING THE ENGINE 
IDLING SPEED on page 3-9.
8. Adjust:  Throttle body...

ENGINE
3-8
Make sure that the vacuum pressure is 
within specification.
10. Stop the engine and remove the measuring  equipment.
11. Adjust:
 Throttle cable free playRefer to ADJUSTING THE THROTTLE 
CABLE FREE PLAY on page 3-9.
12. Install:  Synchronizing hoses
Fuel tankRefer to FUEL TANK on page 7-1.
 Rider and passenger seat Refer to GENERAL CHASSIS on page 4-
1.
EAS20600
ADJUSTING THE EXHAUST GAS VOLUME
NOTE:
Be sure to set the CO density level to stan-
dard, and then adjust the exhaust gas...

ENGINE
3-9
8. Simultaneously press the “SELECT” and “RESET” buttons to return to the cylinder 
selection (step 5).
9. Turn the main switch to “OFF” to cancel the  mode.
EAS20610
ADJUSTING THE ENGINE IDLING SPEED
NOTE:
Prior to adjusting the engine idling speed, the 
throttle bodies’ synchronization should be 
adjusted properly, the air filter element should 
be clean, and the engine should have ade-
quate compression.
1. Start the engine and let it warm up for sev-
eral minutes.
2. Install:
 Digital...

ENGINE
3-10
c. Tighten the locknut.
WARNING
EW2D1001
After adjusting the throttle cable free play, 
start the engine and turn the handlebars to 
the right and to the left to ensure that this 
does not cause the engine idling speed to 
change.
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EAS20680
CHECKING THE SPARK PLUGS
The following procedure applies to all of the 
spark plugs.
1. Remove: Radiator upper bolts
 Radiator lower bolt
Refer to RADIATOR on page 6-1.
2. Remove:
 Ignition coils
 Spark plugs
CAUTION:...

ENGINE
3-11
CAUTION:
ECA13340
Before removing the spark plugs, use com-
pressed air to blow away any dirt accumu-
lated in the spark plug wells to prevent it 
from falling into the cylinders.
4. Install: Compression gauge “1”
 Extension
5. Measure:  Compression pressure
Out of specification  → Refer to steps (c) 
and (d).
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a. Set the main switch to “ON”.
b. With the throttle wide open, crank the  engine until the reading on the compres-
sion gauge stabilizes.
WARNING...

ENGINE
3-12
CAUTION:
ECA13360
 Engine oil also lubricates the clutch and the wrong oil types or additives could 
cause clutch slippage. Therefore, do not 
add any chemical additives or use engine 
oils with a grade of CD “c” or higher and 
do not use oils labeled “ENERGY CON-
SERVING II” “d” or higher.
 Do not allow foreign materials to enter the 
crankcase.
NOTE:
Before checking the engine oil level, wait a few 
minutes until the oil has settled. 4. Start the engine, warm it up for several 
minutes,...

ENGINE
3-13
5. If the oil filter cartridge is also to be replaced, perform the following procedure.
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a. Remove the oil filter cartridge “1” with an oil filter wrench “2”.
b. Lubricate the O-ring “3” of the new oil filter  cartridge with a thin coat of engine oil.
CAUTION:
ECA13390
Make sure the O-ring “3” is positioned cor-
rectly in the groove of the oil filter car-
tridge.
c. Tighten the new oil filter cartridge to speci-fication with an oil filter wrench....

ENGINE
3-14
to measure the engine oil pressure after 
warming up the engine.
3. Remove: Oil gallery bolt “1”
WARNING
EWA12980
The engine, muffler and engine oil are 
extremely hot.
4. Install: Oil pressure gauge “1”
 Adapter “2”
5. Measure:  Engine oil pressure(at the following conditions)
NOTE:
Regarding the oil pressure as its own data may 
fluctuate depending on the oil temperature and 
viscosity, the oil pressure may fluctuate when 
measuring. The followi ng data should be used 
only as a...

ENGINE
3-15
2. Adjust Clutch cable free play
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Handlebar side
a. Turn the adjusting dial “1” in direction “b” or  “c” until the specified clutch cable free play 
is obtained.
NOTE:
If the specified clutch cable free play cannot be 
obtained on the handlebar side of the cable, 
use the adjusting nut on the engine side.
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Engine side
a. Loosen the locknut “1”
b. Turn the adjusting nut “2” in direction “a” or 
“b”...