EM -52
ENGINE DOHC
INSPECTION
E005DAEA
PISTONS AND PISTON PINS
1.
Check each piston for scuffing, scoring, wear and
other defects. Replace any piston that is defective.
2.
Check each piston ring for breakage, damage and
abnormal wear. Replace the defective rings.
When the piston requires replacement, its rings
should also be replaced.
3.
Check that the piston pin fits in the piston pin hole.
Replace any piston and pin assembly that is defective.
The piston pin must be smoothly pressed by hand into
the pin hole (at room temperature).
PISTON RINGS
1.
Measure the piston ring side clearance. If the mea-
sured value exceeds the service limit, insert a new
ring in the ring groove to measure the side clearance.
If the clearance still exceeds the service limit, replace
the piston and rings together. If it is less than the
service limit, replace the piston rings only.
Piston ring side clearance
No.1 : 0.04 ~ 0.085 mm (0.0016 ~ 0.0033 in.)
No. 2 : 0.04 ~ 0.085 mm (0.0016 ~ 0.0033 in.)
Limit
No. 1 : 0.1 mm (0.004 in.)
No. 2 : 0.1 mm (0.004 in.)
ECKD001G
2.
To measure the piston ring end gap, insert a piston
ring into the cylinder bore. Position the ring at right
angles in the cylinder wall by gently pressing it down
with a piston. Measure the gap with a feeler gauge. If
the gap exceeds the service limit, replace the piston
ring.
Piston ring end gap
[Standard dimensions]
No. 1 : 0.15 ~ 0.30 mm (0.0059 ~ 0.012 in.)
No. 2 : 0.30 ~ 0.45 mm (0.012 ~ 0.018 in.)
Oil ring side rail : 0.2 ~ 0.7 mm (0.0079 ~ 0.0276 in.)
[Limit]
No. 1, No. 2 : 1.0 mm (0.039 in.)
Oil ring side rail : 1.0 mm (0.0.39 in.)
ECKD001K
When replacing the ring without correcting the cylin-
der bore, check the gap with the ring situated at the
low part of cylinder that is less worn out.
ZENITH POWER PRODUCTS - 416
