Honda WT30XK4 Manual page 106

PISTON PIN O.D.
Measure and record the piston pin O.D. at three points
(both ends and middle). Take the minimum reading to
determine piston pin O.D.
WT30XK4:
STANDARD: 17.994 – 18.000 mm
(0.7084 – 0.7087 in)
SERVICE LIMIT: 17.950 mm (0.7067 in)
WT40XK3:
STANDARD: 19.994 – 20.000 mm
(0.7872 – 0.7874 in)
SERVICE LIMIT: 19.950 mm (0.7854 in)
If the measurement is less than the service limit,
replace the piston pin.
Inspect the piston pin bore I.D. (page 13-10).
Inspect the connecting rod small end I. D. (page 13-13)
with this inspection.
PISTON PIN-TO-PISTON PIN BORE
CLEARANCE
Subtract the piston pin O.D. from the piston pin bore
I.D. to obtain the piston pin-to-piston pin bore
clearance.
STANDARD: 0.002 – 0.014 mm (0.0001 – 0.0006 in)
SERVICE LIMIT: 0.08 mm (0.003 in)
If the calculated clearance is more than the service limit,
replace the piston pin (page 13-8) and recheck the
clearance.
If the clearance is still more than the service limit with
the new piston pin, replace the piston (page 13-8).
PISTON RING SIDE CLEARANCE
Measure the clearance between each piston ring and
ring groove of the piston using a feeler gauge.
STANDARD:
Top/second: 0.030 – 0.060 mm
(0.0012 – 0.0024 in)
SERVICE LIMIT:
Top/second: 0.15 mm (0.006 in)
If any of the measurements is more than the service
limit, inspect the piston ring width(page 13-12).
If the piston ring width is normal, replace the piston
(page 13-8) and reinspect the clearance.
If necessary, replace the piston rings (top, second, oil)
as a set (page 13-8) and reinspect the clearance.
If any of the measurements is still more than the service
limit with the new piston rings, replace the piston (page
13-8).
CRANKCASE
13-11