Decompression Valve - Husqvarna K 760 Workshop Manual

11
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
Use a long socket or the
combination spanner to dis-
mantle the decompression valve.
Service
Check that the valve moves.
Clean the valve of soot and
deposits.
Fitting
Clean and check the sealing
washer.
Leakage test
Use a leakage spray or soapy
water. Move the stop switch to
stop position and slowly pull
the starter handle.
Dismantling
Use a long socket or the combination
spanner, 506 38 26-01, to dismantle the
decompression valve.
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.
Fitting
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.