Yamaha YW50P Service Manual page 78

CYLINDER HEAD, CYLINDER A N D PISTON
I ENG I
®
C y l i n d e r bore
IJCF,
S t a n d a r d
4 0 . 0 0 0 ~ 4 0 . 0 1 4 m m
(1.5748~ 1.5754 in)
W e a r l i m i t
40.10 m m
(1.5787 in)
- 0 . 0 5
m m
(0.0020 in)
T a p e r " T "
O u t of r o u n d - 0.03 mm
"
R" (0.0012 in)
C = M a x i m u m D
T=( M a x i m u m D1 o r D2 ) - ( M a x i m u m D5 or
D6 )
R=( M a x i m u m D1 D3 or D5 ) - ( M a x i m u m D2
D4 or D6 )
• If o u t o f s p e c i f i c a t i o n , r e b o r e or r e p l a c e cyl-
inder, a n d r e p l a c e p i s t o n a n d p i s t o n r i n g s
as a set.
2 n d step:
• M e a s u r e t h e p i s t o n skirt d i a m e t e r
" p "
w i t h
a m i c r o m e t e r .
( ~ 10 m m f r o m t h e p i s t o n b o t t o m edge.
I l st°nsze
I
3 9 . 9 5 8 ~ 3 9 . 9 7 2 m m ( 1 . 5 7 3 1 ~ 1 . 5 7 3 7 in)
• If o u t of s p e c i f i c a t i o n , replace p i s t o n a n d pis-
t o n r i n g s as a set.
3rd step:
• C a l c u l a t e t h e p i s t o n - t o c y l i n d e r c l e a r a n c e
w i t h f o l l o w i n g f o r m u l a :
I P i s t o n - t o c y l i n d e r c l e a r a n c e = C y l i n d e r bore I
I
"
C "- Piston skirt d i a m e t e r
" p "
I
• If o u t of s p e c i f i c a t i o n , r e b o r e or r e p l a c e cyl-
i n d e r , a n d r e p l a c e p i s t o n a n d p i s t o n r i n g s as
a set.
P i s t o n - t o c y l i n d e r c l e a r a n c e :
0.035 - 0 . 0 4 0 m m (0.014 - 0.0016 in)
L i m i t : 0.10 m m (0.0039 in)
4-6