Husqvarna SM 610 2006 Workshop Manual page 81

E N G IN E O V E R H A U L IN G
R e p la c in g th e va lve g u id e
C h a n g e th e va lv e g u id e a s fo llo w s:
- P u t th e h e a d in a n o ve n h e a te d a t a te m p e ra tu re a f 2 0 0 °C (3 9 2 ° F ), a n d le t
it th e re fo r 1 h o u r; d rive th e va lve o u t w ith a d rift a n d a llo w to co o l; c h e ck th e
co n d itio n o f th e va lve se a ts.
- C h o o se a su ita b le va lve g u id e ta kin g in to a cco u n t th a t cle a ra n ce s a t a s-
se m b ly a re 0 .0 0 0 8 7 ÷0 .0 0 2 0 in .: sp a re s a re su p p lie d w ith a n o ve rsize d e xte r-
n a l d ia m e te r (Ø 0 .4 7 in .) o f: 0 .0 0 0 9 8 /0 .0 0 1 9 7 in . (th e se va lve s g u id e s a re
m a rke d w ith R E D a n d B L U E co lo rs re sp e ctive ly; th e se d istin g u ish in g m a rks
a re o n th e h e a d );
- R e h e a t th e c ylin d e r h e a d a t a te m p e ra tu re o f 2 0 0 °C /3 9 2 °F ;
- L u b rica te th e s e a t w ith e n g in e o il th e n in se rt th e g u id e va lve (K e e p a t a m b i-
e n t te m p e ra tu re : 2 0 °C /6 8 °F ) u sin g a su ita b le d rift; lu b rica tin g w ith
M O L IK O T E G ;
- R e a m th e in te rn a l h o le (A ) a n d lu b rica te ;
- F it th e lo w e r va lve sp rin g co lle cts, lu b rica te a n d fit th e n e w se a l rin g s.
V a lve
C h e ck th a t th e va lve ste m a n d co n ta ct su rfa ce s a re in g o o d co n d itio n . T h e re
sh o u ld b e n o p ittin g , cra cks, d isto rtio n s o r sig n s o f w e a r. C a rry o u t th e fo llo w -
in g ch e cks:
- C h e ck th e va lve ste m fo r d isto rtio n b y re stin g it o n a V -b lo ck a n d m e a su rin g
th e d isto rtio n w ith a co m p a ra to r.
W e a r lim it: 0 .0 0 1 9 7 in .
- C h e ck th e co n ce n tricity o f th e va lve h e a d b y re stin g a n a n g le co m p a ra to r
a g a in st th e h e a d a n d th e n ro ta te th e va lve in a V -b lo ck.
W e a r lim it: 0 .0 0 1 2 in .
7
B : d istin g u ish in g co lo r a re a
C : in ta ke a n d e xh a u st= 4 7 m m (1 .8 5 in )