KEEWAY Focus, Maintenance Manual

Page: 43 / 115

43
with a new one.
The end gap of each ring is to be measued with the ring fitted squarely into the cylidner bore and
held at the least worn part near the cylidner bottom, as shown in the illustration.
Service limit
：
0.75mm(0.030in)
As the piston ring wears, its end gap increases reducing
reducing engine power output becaust of the resultant blow
by through the enlarged gap. Here lies the importance of
using piston rings with end gaps with the limit. Measure the
piston ring free end gap to check the spring tension.
service limit
：
3.6mm(0.14in)
Fix the piston ring in the piston ring groove, measure
the ring side clearance with the thicknes gauge while matching
the sliding surface of piston and ring.
Standard clearance
1st
： ： ： ：
0.04-0.06mm(0.0016-0.0024in)
2nd
：
0.02-0.04mm(0.0008-0.0016in)
Reed vakve
Check the clearance A between reed valve and its seat
and the dimension B. If the clearance A is noted to exceed
0.2mm, replace the reed valve assembly. The dimension B is at
least 1mm.