Standard Dimensions, Wear Tolerances - Husqvarna 324LX Workshop Manual

6
Cylinder block and valve mechanism
2
1
38
Dismantle the crankshaft and the cam
belt.
Pull away the sealing rings from the
crankshaft .
Dismantle the valves.
Press together the spring with your
thumbs and remove the valve disc.
Lift out the valve spring and the valve.
Check the component parts with regard
to damage and wear.

Standard dimensions, wear tolerances

Component
Valve spring length
Valve spindle diameter, exhaust
Valve spindle diameter, inlet
Valve guide inner diameter
Clearance, valve spindle/valve guide, exhaust
Clearance, valve spindle/valve guide, inlet
Timing gear inner diameter
Cam height
NOTE!
When the valve guides are worn in excess of the wear tolerances these
cannot be changed separately but the entire cylinder block must be
replaced with a new one.
Clean the valves and grind them in
using valve grinding compound.
Clean the valves thoroughly before
assembling.
The valves are marked:
HI = inlet valve
HE = exhaust valve
Lift up the crankcase and pull the piston
out of the cylinder bore.
NOTE!
Note the cam belt's direction of
rotation (for example, from which
direction the text on the belt can
be read) so it rotates in the same
direction when reassembled.
Pull away the sealing rings from the
crankshaft .
Dismantle the valves.
Insert a rolled-up cloth in the cylinder
bore to support the valves when
dismantling the valve discs.
Press down valve disc with your
thumbs and move it to the adjacent cut-
out.
Lift out the disc, valve spring and valve.
Standard
20.66 mm
3.435 – 3.450 mm
3.470 – 3.485 mm
3.500 – 3.518 mm
0.050 – 0.083 mm
0.015 – 0.048 mm
4.020 – 4.050 mm
22.097 mm
Clean off any deposits from the valves
(especially the exhaust valve) using a
wire brush.
Check the valve head for signs of
cracking.
Small unevenness can be ground away
using valve grinding compound.
Apply a thin layer of bearing paste on
the valve head. Insert the valve in the
guide and rotate it back and forth.
Repeat the procedure until a matt, grey,
unbroken stripe (approximately 0.8 mm
wide) is visible around the head and
valve seating.
Clean the valves thoroughly before
assembling.
Wear limit
20.00 mm
3.380 mm
3.400 mm
3.560 mm
0.120 mm
0.098 mm
4.100 mm
21.797 mm