KOHLER #A- 271329 ( M O D E L XG) GAS CARBURETOR
The Model XG c a r b u r e t o r i s a l s o of the v e n t u r i - n o z z l e type s t r a i g h t g a s c a r b u r e t o r s u i t a b l e f o r
N a t u r a l and
g a s . The XG f e a t u r e s a n " E c o n o m i z e r " unit which a u t o m a t i c a l l y p r o v i d e s a r i c h
power m i x t u r e when the engine i s u n d e r h e a v y load and a l e a n e r e c o n o m y m i x t u r e f o r p a r t load and
p a r t t h r o t t l e o p e r a t i o n . A d i a p h r a g m i n the e c o n o m i z e r i s a c t u a t e d by manifold v a c u u m which i s
a p p l i e d t o the unit t h r o u g h the c o m b i n e d i d l e - e c o n o m i z e r line.
T h e idle l i n e , which e x t e n d s t o the
s e c o n d a r y r e g u l a t o r , p r o v i d e s s u f f i c i e n t g a s f o r o p e r a t i o n a t low i d l e s p e e d s when the velocity of a i r
t h r o u g h the
is
t o o low t o d r a w enough f u e l t o s u s t a i n o p e r a t i o n . When the e c o n o m i z e r f e a t u r e
is
u s e d , the idle l i n e i s u s u a l l y e x t e n d e d
m e a n s of a T e e t o c o n n e c t o n the intake manifold s i d e of
the t h r o t t l e p l a t e ( l o w e r flange on c a r b u r e t o r ) . With t h i s a r r a n g e m e n t , the idle a d j u s t m e n t i s m a d e on
the r e g u l a t o r .
The XG c a r b u r e t o r a l s o f e a t u r e s a s e p a r a t e s t a r t i n g s y s t e m which b l o c k s off the m a i n s y s t e m t o
p r o v i d e a r i c h m i x t u r e f o r s t a r t i n g . The s t a r t i n g m i x t u r e s y s t e m o p e r a t e s only when the choke i s
fully c l o s e d . The choke i s in e i t h e r f u l l open o r f u l l c l o s e d p o s i t i o n with no i n t e r m e d i a t e p o s i t i o n s .
When the choke i s c l o s e d , the s m a l l volume of a i r needed i s d r a w n t h r u a s m a l l hole i n the choke p l a t e .
O p e r a t i o n : The XG c a r b u r e t o r functions m u c h the s a m e a s the p r e v i o u s l y d e s c r i b e d m o d e l KG1 c a r -
b u r e t o r . R e f e r t o o p e r a t i o n s e c t i o n o n t h a t c a r b u r e t o r f o r e x p l a n a t i o n of o p e r a t i n g p r i n c i p l e s .
A d j u s t m e n t s : R e f e r t o F i g u r e 12-5 f o r i n i t i a l s e t t i n g s on c a r b u r e t o r . A f t e r i n i t i a l a d j u s t m e n t i s
m a d e , s t a r t engine a n d m a k e f i n a l a d j u s t m e n t s a s follows:
1 .
A f t e r engine s t a r t s , hold choke in c l o s e d position while making f i n a l s t a r t i n g m i x t u r e
a d j u s t m e n t . Move s t a r t i n g a d j u s t m e n t t o obtain m a x i m u m s p e e d then continue adjusting
r i c h e r u n t i l s p e e d d r o p s s l i g h t l y - - r e t i g h t e n locknut a t this s e t t i n g then r e t u r n choke t o full
open p o s i t i o n .
2.
Allow engine t o w a r m up then m o v e t h r o t t l e c o n t r o l t o idle position. A d j u s t i d l e s p e e d
s t o p i f needed t o a t t a i n p r o p e r i d l e s p e e d ( c h e c k with hand t a c h o m e t e r ) then move idle
a d j u s t m e n t s c r e w (on r e g u l a t o r ) until s m o o t h e s t idle i s a t t a i n e d .
3.
Open t h r o t t l e a n d p l a c e engine u n d e r n o r m a l load.
T u r n load a d j u s t m e n t in until s p e e d
d r o p s ( l e a n s e t t i n g ) then t u r n a d j u s t m e n t h a c k out u n t i l s p e e d a g a i n i n c r e a s e s then d r o p s
f r o m a n
s e t t i n g - - m o v e a d j u s t m e n t halfway b e t w e e n l e a n and r i c h s e t t i n g s f o r b e s t
m i x t u r e u n d e r n o r m a l l o a d conditions.
Reconditioning: No r e g u l a r s e r v i c e i s r e q u i r e d on the XG c a r b u r e t o r .
If
reconditioning b e c o m e s
n e c e s s a r y , c o m p l e t e l y d i s a s s e m b l e c a r b u r e t o r and r e p l a c e a l l g a s k e t s , d u s t s e a l s and w o r n o r d a m -
a g e d p a r t s . The d i a p h r a g m i n the e c o n o m i z e r should a l s o b e r e p l a c e d d u r i n g reconditioning. T h o r -
oughly w a s h a l l p a r t s in s o l v e n t a n d blow out a l l p a s s a g e s with c o m p r e s s e d a i r . A f t e r r e a s s e m b l i n g
and r e i n s t a l l i n g c a r b u r e t o r , c h e c k a l l c o n n e c t i o n s and g a s k e t j o i n t s f o r e v i d e n c e of l e a k a g e .
