ENGINE -GENERAL SERVICES
COOLING
On e n g i n e s w i t h t h e s t a n d a r d f o r c e d a i r cooling s y s t e m , r o t a t i o n of the b l a d e s o r f i n s on the f l y -
wheel c a u s e s cooling a i r t o b e d r a w n in t h r o u g h the r o t a t i n g a i r s c r e e n w h e r e i t is f o r c e d t h r o u g h the
b l o w e r h o u s i n g a n d b a f f l e s p a s t the cooling f i n s on c y l i n d e r b l o c k a n d h e a d s w h e r e i t i s f i n a l l y e j e c t e d
a s h e a t e d a i r t o w a r d t h e r e a r of the engine.
In a l l a p p l i c a t i o n s , r e c i r c u l a t i o n of the h e a t e d a i r m u s t
b e
a v o i d e d - - m a k e s u r e a i r h e a t e d b y the engine cannot b e d r a w n b a c k i n t o t h e a i r i n t a k e .
The r o t a t i n g a i r s c r e e n a n d cooling f i n s m u s t b e k e p t c l e a n a n d u n o b s t r u c t e d a t a l l t i m e s . DO
NOT o p e r a t e engine with b l o w e r h o u s i n g , b a f f l e s o r any o t h e r cooling s h r o u d s r e m o v e d a s t h i s
r e s u l t i n i m p r o p e r c i r c u l a t i o n p a s t the cooling f i n s a n d o v e r h e a t i n g .
O t h e r e x t e r n a l s u r f a c e s of a n e n g i n e should a l s o h e k e p t f r e e of oil and d i r t a c c u m u l a t i o n .
T h i s
s h o u l d b e done not only f o r s a f e t y a n d a p p e a r a n c e b u t b e c a u s e p o o r cooling e f f i c i e n c y r e s u l t s f r o m
d i r t y e x t e r n a l s u r f a c e s on engine and c o m p o n e n t s .
CYLINDER HEAD SERVICE
A f t e r e a c h 500 h o u r s of o p e r a t i o n , the c y l i n d e r h e a d s s h o u l d b e t a k e n off the engine and s e r v i c e d .
R e m o v e c a r b o n d e p o s i t s f r o m c o m b u s t i o n c h a m b e r i n head. S c r a p e a n d r e m o v e c a r b o n with a s h a r p
p i e c e of wood--wood o r s i m i l a r m a t e r i a l
is
s u g g e s t e d t o a v o i d s c r a t c h i n g a l u m i n u m s u r f a c e s of head.
Always u s e new c y l i n d e r head g a s k e t s , m a k e s u r e head b o l t s a r e tightened i n t h e p r o p e r s e q u e n c e and
t o the t o r q u e value s t a t e d in the S p e c i f i c a t i o n Section. B e f o r e r e i n s t a l l i n g the s e r v i c e d h e a d s , c h e c k
a n d a d j u s t v a l v e - t a p p e t c l e a r a n c e p e r the following i n s t r u c t i o n s .
VALVE - TAPPET CLEARANCE
A f t e r e a c h 500 h o u r s , c h e c k c l e a r a n c e b e t w e e n t h e v a l v e s t e m s a n d t a p p e t s .
T h e engine m u s t h e
s t o p p e d a n d cooled t o n o r m a l a m b i e n t t e m p e r a t u r e s t o a c c u r a t e l y g a u g e a n d a d j u s t v a l v e c l e a r a n c e s .
U s e
t h e following p r o c e d u r e t o a d j u s t :
1.
T u r n e n g i n e o v e r until p i s t o n i n
c y l i n d e r ( c l o s e s t to flywheel) i s a t Top Dead C e n t e r on
c o m p r e s s i o n - - i n t h i s p o s i t i o n , both v a l v e s will b e c l o s e d and c a m will have no a f f e c t on
t a p p e t .
2.
M e a s u r e c l e a r a n c e b e t w e e n valve s t e m and t a p p e t with a f e e l e r gauge.
T o a d j u s t , t u r n
a d j u s t i n g s c r e w on t a p p e t in o r o u t until p r o p e r c l e a r a n c e
is
a t t a i n e d .
CLEARANCE S P E C .
K532
K662
I n t a k e valve
- -
cold c l e a r a n c e
-
-
E x h a u s t valve
--
cold c l e a r a n c e
0 1 7
-
-
3 .
A f t e r a d j u s t i n g v a l v e - t a p p e t c l e a r a n c e o n
c y l i n d e r , t u r n engine o v e r u n t i l
c y l i n d e r i s
a t TDC o n c o m p r e s s i o n a n d r e p e a t a d j u s t m e n t on t h i s c y l i n d e r .
4.
A f t e r v a l v e s a r e in p r o p e r a d j u s t m e n t , p o s i t i o n new h e a d g a s k e t s and r e i n s t a l l c y l i n d e r
h e a d s . Make s u r e h e a d b o l t s a r e tightened i n
p r o p e r s e q u e n c e a n d t o the t o r q u e value
s p e c i f i e d o n p a g e 14.3.
