Cylinder/Piston - Husqvarna K1270 Workshop Manual

16. CYLINDER/PISTON

16.1. COMPRESSION TEST
The compression test indicates leakage from the
combustion chamber. If the machine lacks engine
power and is difficult to start this may be due to
poor compression.
Close the decompression valve or fit the sealing
plug 503 55 22-01 to eliminate the decompression
valve as the source of the fault.
COMPRESSION TESTER
The compression test is performed using the
measurement instrument 531 03 16-86, which is
connected to the spark plug hole. The valve below
the gauge evacuates the pressure.
COMPRESSION TEST
– Run the engine warm for a few minutes.
– Unscrew the spark plug and connect the
instrument.
– Make 5–6 attempts to start with a closed
decompression valve and read the pressure on
the gauge. Evacuate the pressure and repeat
the procedure a few times. Note the average
value for the tests.
The average value for a new and run-in engine is
approximately 7.5 bar (110 psi). Values less than
5.5 bar (80 psi) indicate faults with on the cylinder,
piston or piston rings.
16.2. CYLINDER
DISMANTLING
1. Remove the cutting head and cutting arm.
2. Remove the cylinder cover, the carburettor and
the muffler.
3. Remove the four mounting screws of the cylindr
and lift the cylinder up.
COMPRESSION TEST
DISMANTLING
Cylinder/Piston
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