Cylinder And Piston - Husqvarna K970 III Workshop Manual

6.7.2 To remove the decompression valve
• Remove the decompression valve with a long socket
or the combination wrench.
6.7.3 To examine the decompression valve
1. Make sure that the decompression valve moves.
2. Clean the decompression valve.
3. Apply leakage spray or soap water on the
decompression valve before installation.
4. Install the decompression valve, refer to
the decompression valve on page 43 .
5. Move the stop button to the stop position.
6. Slowly pull the starter rope handle and make sure
that there are no leaks from the decompression
valve.
1444 - 001 - 02.04.2020
6.7.4 To install the decompression valve
1. Clean and examine the sealing washer.
2. Install the decompression valve.

6.8 Cylinder and piston

6.8.1 To examine the compression of the cylinder
The test shows leakage from the combustion chamber.
1. Operate the engine for some minutes until it is
warm.
2. Close the decompression valve or put in the sealing
plug. Refer to
To install
3. Remove the spark plug.
4. Connect the compression tester to the spark plug
hole.
5. Pull the starter rope 5-6 times and read the pressure
on the gauge. Remove the pressure from the
cylinder and do the procedure some more times.
6. Make a note of the average of the tests.
The average for a new engine is approximately 7.5
bar/110 psi. Values less than 5.5 bar/80 psi show faults
with or on the cylinder, piston or piston rings.
Servicing tools overview on page 10 .
Repair and servicing - 43