Yamaha Mt 01 T 2005 Manual

							CAMSHAFTS
5-22
3. Remove:
Camshaft drive gear “1”
Camshaft driven gear “2”
Straight keys
Front cylinder camshaft end cover
NOTE:
Cover the crankcase hole with a clean rag “3” to 
prevent the straight keys from falling into the 
crankcase.
4. Remove:
Oil delivery pipe “1”
Camshaft cover “2”
(along with the camshafts)
NOTE:
Loosen each bolt 1/4 of a turn at a time, in stag-
es and in a crisscross pattern. After all of the 
bolts are fully loosened, remove them.
EAS23860CHECKING THE CAMSHAFTS
1. Check:
Cam
Blue discoloration/pitting/scratches → Re-
place the camshaft.
2. Measure:
Cam dimensions “a” and “b”
Out of specification → Replace the camshaft.
 
Camshaft lobe dimensions
Intake A
38.241–38.341 mm (1.5055–
1.5095 in) (cylinder #1)
38.243–38.343 mm (1.5056–
1.5096 in) (cylinder #2)
Limit
38.141 mm (1.5016 in) (cylinder 
#1)
38.143 mm (1.5017 in) (cylinder 
#2)
Intake B
31.950–32.050 mm (1.2579–
1.2618 in)
Limit
31.850 mm (1.2539 in)
Exhaust A
38.236–38.336 mm (1.5054–
1.5093 in)
Limit
38.136 mm (1.5014 in)
Exhaust B
31.950–32.050 mm (1.2579–
1.2618 in)
Limit
31.850 mm (1.2539 in) 
						

							CAMSHAFTS
5-23
3. Measure:
Camshaft journal diameter (crankcase side) 
“a”
Out of specification → Replace the camshaft.
4. Measure:
Camshaft journal diameter (camshaft cover 
side) “a”
Out of specification → Replace the camshaft.
5. Measure:
Crankcase hole inside diameter “a”
Out of specification → Replace the crank-
case.6. Measure:
Camshaft cover hole inside diameter “a”
Out of specification → Replace the camshaft 
cover.
7. Calculate:
Camshaft-to-crankcase clearance
Out of specification → Replace the defective 
part(s).
NOTE:
Calculate the clearance by subtracting the 
crankcase side camshaft journal diameter 
(crankcase side) from the crankcase hole inside 
diameter.
8. Calculate:
Camshaft to camshaft cover clearance
Out of specification → Replace the defective 
part(s).
 
Camshaft journal diameter 
(crankcase side) 
24.942–24.965 mm (0.9820–
0.9829 in)
 
Camshaft journal diameter 
(camshaft cover side) 
27.967–27.980 mm (1.1011–
1.1016 in)
 
Crankcase hole inside diameter
25.000–25.021 mm (0.9843–
0.9851 in)
 
Camshaft cover hole inside 
diameter
28.000–28.021 mm (1.1024–
1.1032 in)
 
Camshaft to crankcase clearance
0.050–0.084 mm (0.0020–0.0033 
in) 
						

							CAMSHAFTS
5-24
NOTE:
Calculate the clearance by subtracting the cam-
shaft journal diameter (camshaft cover side) 
from the camshaft cover hole inside diameter.
9. Check:
Camshaft drive gears
Camshaft driven gears
Chips/pitting/roughness/wear → Replace the 
defective part(s).
EAS23890
CHECKING THE ROCKER ARMS AND 
ROCKER ARM SHAFTS
The following procedure applies to all of the 
rocker arms and rocker arm shafts.
1. Check:
Rocker arm
Damage/wear → Replace.
2. Check:
Rocker arm shaft
Blue discoloration/excessive wear/pitting/ 
scratches → Replace or check the lubrication 
system.
3. Measure:
Rocker arm inside diameter “a”
Out of specification → Replace.
4. Measure:
Rocker arm shaft outside diameter “a”
Out of specification → Replace.5. Calculate:
Rocker arm to rocker arm shaft clearance
NOTE:
Calculate the clearance by subtracting the rock-
er arm shaft outside diameter from the rocker 
arm inside diameter.
Above 0.08 mm (0.003 in) → Replace the de-
fective part(s).
EAS23900
CHECKING THE ROCKER ARM BASES
1. Check:
Rocker arm base
Cracks/damage → Replace.
EAS23910CHECKING THE PUSH RODS
1. Check:
Push rod
Push rod end
Bends/damage → Replace.
2. Measure:
Push rod runout
Out of specification → Replace.
 
Camshaft to camshaft cover 
clearance
0.020–0.054 mm (0.0008–0.0021 
in)
 
Rocker arm inside diameter
18.000–18.018 mm (0.7087–
0.7094 in)
Limit
18.036 mm (0.7101 in)
 
Rocker arm shaft outside 
diameter
17.976–17.991 mm (0.7077–
0.7083 in)
 
Rocker-arm-to-rocker-arm-shaft 
clearance
0.009–0.042 mm (0.0004–0.0017 
in)
 
Valve push rod runout
0.3 mm (0.012 in) 
						

							CAMSHAFTS
5-25
EAS23920
CHECKING THE VALVE LIFTERS AND 
VALVE LIFTER CASES
1. Check:
Valve lifter
Blue discoloration/excessive wear/pitting/ 
scratches → Replace and check the lubrica-
tion system.
2. Check:
Valve lifter case “1”
Damage/wear → Replace the valve lifter 
case.
Seal “2”
O-ring “3”
Damage/wear → Replace the O-ring.
3. Measure:
Valve lifter outside diameter “a”
Out of specification → Replace.4. Measure:
Valve lifter case inside diameter “a”
Out of specification → Replace.
5. Calculate:
Valve lifter-to-valve lifter case clearance
NOTE:
Calculate the clearance by subtracting the valve 
lifter case outside diameter.
Above 0.072 mm (0.0028 in) → Replace the 
defective part(s).
EAS23930CHECKING THE PUSH ROD COVER
1. Check:
Push rod cover
Cranks/damage → Replace.
Seal
 
Valve lifter outside diameter 
(intake)
22.962–22.974 mm (0.9040–
0.9045 in)
Valve lifter outside diameter 
(exhaust)
22.962–22.974 mm (0.9040–
0.9045 in)
 
Valve lifter hole inside diameter 
(intake)
23.000–23.021 mm (0.9055–
0.9063 in)
Valve lifter hole inside diameter 
(exhaust)
23.000–23.021 mm (0.9055–
0.9063 in)
 
Valve-lifter-to-valve-lifter-hole 
clearance
0.026–0.059 mm (0.0010–0.0023 
in) 
						

							CAMSHAFTS
5-26
O-ring
Damage/wear → Replace the oil seal and O-
ring as a set.
EAS23980CHECKING THE DECOMPRESSION SYSTEM
1. Check:
Decompression system
NOTE:
Check the decompression system while the 
decompression push rod is installed in the 
camshaft.
Check that the decompression pin “1” projects 
from the camshaft.
Check that the decompression push rod “2” 
moves smoothly.
2. Check:
Decompression push rods
Bends/damage → Replace.
EAS23990CHECKING THE OIL DELIVERY PIPE
1. Check:
Oil delivery pipe
Damage → Replace.
Obstruction → Wash and blow out with com-
pressed air.
O-rings
Damage/wear → Replace.
EAS24030
INSTALLING THE CAMSHAFTS
1. Install:
Camshafts
(to the camshaft cover)
NOTE:
Lubricate molybdenum disulfide oil onto the 
camshaft journals and lobes.
Align the punch mark “a” on the rear cylinder 
camshaft with the punch mark “b” on the front 
cylinder camshaft.2. Install:
Camshaft cover “1”
(along with the camshafts)
Camshaft oil delivery pipe “2”
NOTE:
Tighten the camshaft cover bolts in stages and 
in a crisscross pattern.
3. Install:
Front cylinder camshaft end cover “1”
NOTE:
Install the front cylinder camshaft end cover “1” 
with its punch marks “a” aligned vertically.
Finger-tighten the bolts.
4. Install:
Straight keys
Camshaft drive gear “1”
Camshaft driven gear “2”
NOTE:
Cover the crankcase hole with a clean rag “3” 
to prevent the straight keys from falling into the 
crankcase.
a
1 
						

							CAMSHAFTS
5-27
Align the punch mark “a” on the camshaft drive 
gear “1” with the punch mark “b” on the cam-
shaft driven gear “2”.
Insert a cross-headed screwdriver into one of 
the holes in the outer camshaft driven gear and 
rotate the gear until the teeth of both driven 
gears are aligned. The teeth of both camshaft 
driven gears must be aligned for installation.
5. Tighten:
Camshaft driven gear nut “1”
NOTE:
Place a folded copper washer “2” between the 
teeth of the camshaft drive gear and camshaft 
driven gear in order to lock them.
Do not damage the teeth of the camshaft drive 
and camshaft driven gear.
After tightening the camshaft driven gear nut, 
remove the copper washer to clean the teeth of 
the camshaft drive gear and camshaft driven 
gear.6. Tighten:
Camshaft drive gear bolt “1”
Front cylinder camshaft end cover bolts “2”
NOTE:
Place a folded copper washer “3” between the 
teeth of the camshaft drive gear and camshaft 
driven gear in order to lock them.
Do not damage the teeth of the camshaft drive 
and camshaft driven gear.
After tightening the camshaft drive gear bolt, 
remove the copper washer to clean the teeth of 
the camshaft drive gear and camshaft driven 
gear.
EAS24050
BLEEDING A VALVE LIFTER
A valve lifter must be bled in the following cases.
When installing a new valve lifter
When the valve lifter leaks oil
1. Bleed:
Valve lifter



 





 
 



 
 



 
 



 
 



 



a. Fill a container with kerosene and place the 
valve lifter into the container as shown.
Pump the plunger side of the valve lifter with 
a press a number of times to let in kerosene.
T R.. 
Camshaft driven gear nut
52 Nm (5.2 m·kg, 37 ft·lb)
T R.. 
Camshaft drive gear bolt
30 Nm (3.0 m·kg, 22 ft·lb)
Front cylinder camshaft end 
cover bolt
7 Nm (0.7 m·kg, 5.1 ft·lb)
LOCTITE
® 
						

							CAMSHAFTS
5-28
CAUTION:
ECA14630
Do not pump the valve lifter excessively.
Kerosene is highly flammable.
b. Install the valve lifter into the engine.
CAUTION:
ECA14650
Be sure to install the valve lifter in its appro-
priate position.
c. Start the engine and warm it up.
d. Stop the engine.
e. Remove the camshaft sprocket cover.
f. Rotate the camshaft until the punch mark “1” 
on the camshaft driven gear aligns with the 
punch mark on the camshaft drive gear as 
shown. This is the condition in which piston 
#1 is at top dead center (TDC).
NOTE:
The crankshaft can be rotated smoothly when 
the spark plugs are removed.
WARNING
EWA12880
Be careful since the engine is hot.
g. With piston #1 at TDC, count the indicated 
number of gear teeth and place marks “2” 
through “5” on the camshaft driven gear as 
shown. When these marks align between the 
centers of the camshaft drive and driven 
gears, the corresponding valve lifter is at its 
highest point.h. Rotate the crankshaft until the mark (on the 
camshaft driven gear) for the valve lifter to be 
bled aligns with the camshaft drive gear as 
shown.
Example:
For bleeding the cylinder-#2 intake valve lift-
er, align mark “2” as shown.
1. Kerosene
2. Valve lifter
1. Piston #1 TDC punch mark
2. Cylinder-#2 intake valve at its highest point
3. Cylinder-#1 exhaust valve at its highest point
4. Cylinder-#1 intake valve at its highest point
5. Cylinder-#2 exhaust valve at its highest point 
						

							CAMSHAFTS
5-29
i. Leave the camshaft drive and driven gears 
aligned for five minutes to allow the valve lift-
er to bleed.
j. If necessary, repeat steps (h) and (i) to bleed 
other valve lifters.
        
EAS24060INSTALLING THE VALVE LIFTERS
1. Install:
Front valve lifter case
Rear valve lifter case
Valve lifters
NOTE:
Install the valve lifter in the correct place.
After installing the valve lifters, fill the tops of 
them with engine oil.
EAS24070INSTALLING THE ROCKER ARMS AND 
PUSH RODS
The following procedure applies to both cylin-
ders.
1. Install:
Rocker arms “1”
Rocker arm shafts “2”
(onto rocker arm base)
NOTE:
The thread hole “a” of the rocker arm shaft must 
face to the outside.
2. Install:
Rocker arm base
(with rocker arms)
Push rods



 





 
 



 
 



 
 



 
 



 



a. Put the rocker arm base on the cylinder head.
b. Install the push rods.
NOTE:
Be sure to correctly install the push rods be-
tween the rocker arms and valve lifters as 
shown. The illustration is viewed from the right 
side of the vehicle.
The lengths of push rod 1 and push rod 2 are 
different. Therefore, be sure to install them in 
the proper position.
Lubricate the push rod end balls with engine 
oil.
1. Piston #1 TDC punch mark
2. Cylinder-#2 intake valve at its highest point 
						

							CAMSHAFTS
5-30
c. Install the rocker arm base bolts (M6) “1”, “2” 
and the rocker arm base bolts (M8) “3”.
NOTE:
Tighten the rocker arm base bolts in stages and 
in a crisscross pattern.
Bolts “1”: l = 36 mm (1.42 in)
Bolts “2”: l = 40 mm (1.57 in)
        
EAS24080
INSTALLING THE CYLINDER HEAD 
COVERS
The following procedure applies to both cylin-
ders.
1. Install:
Front cylinder head cover “1”
Rear cylinder head cover “2”
NOTE:
Apply locking agent (LOCTITE®) to the threads 
of the bolt “3”.
Bolts “3”, “4”: l = 40 mm (1.57 in)
Bolts “5”: l = 50 mm (1.97 in)
Bolt with washer “6”: l = 50 mm (1.97 in)
Bolts “7”: l = 60 mm (2.36 in)
2. Install:
Tappet covers “1”
NOTE:
Install the tappet covers with their “UP” marks “a” 
facing each other.
A. Rear cylinder
B. Front cylinder
1. Intake side rocker arm
2. Exhaust side rocker arm
3. Intake valve lifter
4. Exhaust valve lifter
5.
Push rod 1 l = 288.5 mm (11.358 in)
6.Push rod 2 l = 290.5 mm (11.437 in)
T R.. 
Rocker arm base bolt (M6)
10 Nm (1.0 m·kg, 7.2 ft·lb)
Rocker arm base bolt (M8)
24 Nm (2.4 m·kg, 17 ft·lb)
T R.. 
Cylinder head cover bolt
10 Nm (1.0 m·kg, 7.2 ft·lb)
T R.. 
Tappet cover bolt
10 Nm (1.0 m·kg, 7.2 ft·lb)
1
4
4
5
37LT
7 5
6 7 3
5424 7 6
5
LT
UP
UP
11
a
a 
						

							CYLINDER HEADS
5-31
EAS24110
CYLINDER HEADS
Removing the cylinder heads
Order Job/Parts to remove Q’ty Remarks
Cylinder head covers/Rocker arms Refer to “CAMSHAFTS” on page 5-16.
1 Front exhaust pipe joint 1
2 Front exhaust pipe joint gasket 1
3 Oil pipe 1 1 From crankcase to cylinder heads.
4 Copper washer 4
5 Copper washer 2
6 Engine temperature sensor 1
7 Rear cylinder head 1
8 Front cylinder head 1
9 Cylinder head gasket 2
10 Dowel pin 4
For installation, reverse the removal 
procedure.
ET R..21 Nm (2.1 m • 
kg, 15 ft • Ib)
T R..20 Nm (2.0 m • 
kg, 14 ft • Ib)
T R..18 Nm (1.8 m • 
kg, 13 ft • Ib)
T R..45 Nm (4.5 m • 
kg, 32 ft • Ib)
T R..39 Nm (3.9 m • 
kg, 28 ft • Ib)
7
4
4
9
103
5
9
10
10 2 8 6
1
E
New
New
NewNew
New
New
E
E