Hisun HS250UTV - Page 147

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ENGINE
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1、CHECK
1). Checking the rocker arms
• rocker arm lobes
• valve adjusters
Blue discoloration/pitting/scratches
Replace.
• rocker arms
• rocker arm shafts
Damage/wear
Replace.
a. Check whether the rocker arm is worn out, o
r
damaged and whether the oil hole is blocked.
b. If there is a rocker arm to be replaced, chec
k
the camshaft prominent position of unfairness.
c. Measure the inside diameter of the rocke
r
arm holes .① 。
Out of specification
Replace.
Rocker arm inside diameter repairing limit
value
Φ12.05mm
d. Check the surface of the rocker arm shafts.
Worn/pitting/scratches Replace.
e. Measure the external diameter of rocker arm
shaft with micrometer.
Out of specification
Replace.
Rocker arm shaft outside diameter
repairing limit value
Φ11.96mm
f. Calculate the clearance by subtracting the
rocker arm shaft outside diameter from the
rocker arm inside diameter.
Out of specification
Replace the defective
part(s).
Rocker arm to shaft clearance repairing
limit value
0.06mm
2). Checking the camshaft
ENGINE
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• cam lobes
Pitting/scratches/blue
discoloration
Replace
• camshaft journal
Wear/damage Replace
• Measure the external diameter of camshaft
j
ournal with micrometer.
Out of specification Replace.
• small holes on camshaft sprocket
• rotor “I” mark
Out of alignment
3). Checking the camshaft sprocket
• camshaft sprocket
Wear/damage Replace the camshaft
sprocket and timing chain as a set.
(a)1/4 of a tooth
(b)Correct
① Timing chain
② Sprocket
4). Checking the decompression system
• decompression system
Check while the camshaft sprocket is installed
on the camshaft.
2、INSTALL
1). Installing the rocker arms
• rocker arms
• rocker arm shafts
NOTE:
• After installation, make sure that the thread
hole of the rocker arm shaft is positioned
correctly.
2). Installing the camshaft
• camshaft
• camshaft sprocket