Decompression Valve; Cleaning, Inspection - Husqvarna 545RX Workshop Manual

Cylinder and piston
Dismantle the piston.
505 38 17-05

Decompression valve

Clean the decompression valve and
check that the valve head is not damaged
(burnt) and that the valve operates easily.
If necessary, grind the valve with fi ne-
grained valve grinding compound.
502 54 11-01

Cleaning, inspection

After dismantling, clean the individual components:
1. Scrape carbon deposits from the top of the piston.
2. Scrape carbon deposits from the cylinder's combustion chamber.
3. Scrape carbon deposits from the cylinder's exhaust port.
NOTE!
Scrape carefully with not too sharp a tool so as not to damage the soft
aluminium parts.
4. Wash all the components.
5. Inspect the different components for damage and wear.
Check the piston and cylinder for seizure damage and wear.
Also see the "Analysis and actions" section.
Check the piston ring for wear and damage.
Also see the "Analysis and actions" section.
Check the gudgeon pin.
– If it has blued, it must be replaced.
– If the piston moves too easily both the piston and the gudgeon pin must be replaced.
Check the needle bearing. If it is discoloured or damaged, it must be replaced.
Check the circlips. If they exhibit cracks or are discoloured (caused by overheating),
they must be replaced.
Push the gudgeon pin from the piston us-
ing punch 505 38 17-05.
If the pin is too tight, carefully warm the
piston.
Decompression valve
Clean the decompression valve using a
wire brush. Clean in white spirit or thinner
and blow dry with compressed air.
Check that the hole (A) is not clogged.
Check that the valve moves easily in the
guide and that the valve head is not dam-
aged (burnt).
If necessary, grind the valve into the seat
using fi ne-grained valve grinding com-
pound.
Tip!
Use washer no. 502 54 11-01 as a
friction lining against the valve head
when grinding.
6
43