Husqvarna SM 610 2006 Workshop Manual page 81

E N G IN E O V E R H A U L IN G
R ep lacin g th e valve g u id e
C hange the valv e guide as follow s:
- P ut the hea d in an oven heated at a tem perature af 200 °C (392 ° F ), and let
it there for 1 hour; drive the valve out w ith a drift an d allow to cool; c heck the
condition of the valve seats.
- C hoose a suita ble valve guide taking into account that clearance s at as-
sem bly are 0.0 00 87÷0.0020 in.: sp ares are supplied w ith an oversized exte r-
nal diam eter (Ø 0.47 in.) of: 0.0 0 098/0.00197 in. (these valves guides are
m arked w ith R E D and B LU E colo rs respectively; these distinguishing m arks
are on the head);
- R eheat the c ylinder head at a te m peratu re of 200 °C /392°F ;
- Lubricate the s eat w ith engine o il then insert the guide valve (K eep at am bi-
ent tem pera ture: 20°C /68 °F ) using a suitable drift; lubricating w ith
M O LIK O T E G ;
- R eam the internal hole (A ) and lubricate;
- F it the lo w e r valve spring collects, lubricate and fit the ne w seal ring s.
V alve
C heck that the valve stem and contact surfaces are in good condition. T he re
should be no pitting, cracks, distortions or signs of w e ar. C arry out the follow -
ing checks:
- C heck the valve stem for distortion b y resting it on a V -block and m easuring
the distortion w ith a com parato r.
W ear lim it: 0.00197 in.
- C heck the concentricity of the va lve head b y resting an angle com parator
against the head and then rotate the valve in a V -block.
W ear lim it: 0.0012 in.
7
All manuals and user guides at all-guides.com
B : distinguishing color area
C : intake and e xhaust= 47 m m (1.85 in)