Yamaha RD250 Owner's Manual page 126

r e p l a c i n g t h e p l u g , t h a t y o u a l w a y s c l e a n the g a s k e t
s u r f a c e , t h a t y o u u s e a n e w g a s k e t , a n d t h a t the s p a r k
p l u g is t o r q u e d to 2 . 5 k g - m . ~ 3 . 0 k g - m . A l s o w i p e
off a n y g r i m e t h a t m i g h t be p r e s e n t o n t h e s u r f a c e of
t h e s p a r k p l u g . T h e p l u g c a n be t a k e n out to be c l e a -
n e d a n d g a p p e d . A s l o n g as d e p o s i t b u i l d - u p o n t h e
i n s u l a t o r is not e x t r e m e , y o u c a n u s e a s p a r k p l u g
c l e a n e r to q u i c k l y r e m o v e the d e p o s i t s .
U s e a w i r e t y p e f e e l e r g a u g e to s e t t h e e l e c t r o d e g a p
at 0 . 5 m m . ~ 0 . 6 m m .
S t a n d a r d p l u g
Standard
High land
R D 2 5 0 B / R D 3 5 0 B B - 8 H S (N.G.K.)
B - 7 H S ( N G K )
R D 2 5 0 B / R D 3 5 0 B
(for Europe)
B - 8 E S (N.G.K.)
1 2 0