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 cin g th e va lve g u id e
C h an g e the va lv e g uid e as follo w s:
- P ut th e he a d in a n o ve n hea ted at a te m peratu re a f 2 0 0 °C (3 9 2 ° F ), a nd le t
it th ere fo r 1 h ou r; drive the va lve out w ith a d rift an d a llo w to co o l; c h e ck the
con dition o f the valve se ats.
- C ho ose a suita ble va lve gu id e taking in to acco unt th a t cle a ra n ce s a t a s-
sem b ly are 0.0 0 0 8 7 ÷0 .0 020 in .: sp are s are su pplie d w ith a n o ve rsize d exte r-
na l diam e te r (Ø 0.4 7 in.) of: 0.0 0 09 8/0.0 0197 in. (the se va lve s g u id e s are
m arke d w ith R E D a nd B LU E colo rs respe ctively; the se d istin g u ish in g m arks
are o n the h e ad );
- R eh ea t the c ylind er he ad at a te m peratu re of 20 0 °C /3 9 2 °F ;
- Lu b ricate the s e at w ith en gin e o il then in sert the gu id e va lve (K e e p a t am b i-
en t tem p era tu re: 20 °C /68 °F ) usin g a su itable drift; lub rica tin g w ith
M O L IK O T E G ;
- R ea m th e in te rna l ho le (A ) a nd lubricate;
- F it th e lo w e r valve sp ring colle cts, lub rica te an d fit th e n e w se a l rin g s.
V alve
C h eck tha t the va lve stem an d co ntact surfaces are in g o o d co n d itio n . T he re
sho uld be n o pittin g, cracks, distortio ns or sign s of w e a r. C a rry o u t th e fo llow -
in g che cks:
- C he ck the va lve ste m for d istortion b y restin g it on a V -b lo ck a n d m e asurin g
th e d istortio n w ith a com pa rato r.
W ea r lim it: 0.00 19 7 in.
- C he ck the co nce n tricity o f th e va lve hea d b y restin g a n a n g le co m p a ra tor
ag ain st th e he ad a nd th en ro tate the valve in a V -blo ck.
W ea r lim it: 0.00 12 in .
7
B : distin g uish in g co lo r a rea
C : in ta ke an d e xha ust= 47 m m (1.8 5 in )