Decompression Valve - Husqvarna K 1260 Workshop Manual

12
A
29

DECOMPRESSION VALVE

B
Decompression valve
Function
The decompression valve reduces the compression in the cylinder when
starting.
A limited quantity of fuel/air mixture leaks out through the decompression
valve, as shown in fig. A.
As soon as the engine fires the valve will close due to the combustion
pressure, as in fig. B.
Dismantling
Remove the air filter cover and
the cylinder cover.
Remove the decompression
valve using a box wrench.
Service
Check that the valve moves.
Clean any soot or deposits from
the valve..
Assembly
Clean and check the sealing
washer.
Leakage test
Use a leakage spray or soapy
water. Place the stop switch in
the stop position and pull the
starter handle slowly.
Dismantling
To access the decompression valve, the
air filter cover and the cylinder cover
must be removed.
Remove the decompression valve using
a box wrench.
Service
Check that the valve moves. Carbon
removing chemicals or a light oil
(diesel oil) can help a jammed valve to
work again. Blown clean the valve with
com pressed air. Carbon deposits on the
valve and the seating can be removed
using fine emery cloth.
Assembly
Clean the sealing washer and check that
this is not damaged before assembling
the the decompression valve.
Leakage test
The decompression valve can easily be
checked for leakage without starting the
machine. Use a leakage spray or soapy
water. Move the stop button to the stop
position and slowly pull the starter handle
while observing the decompression valve.