Cleaning Of Components; Assemblies; Cylinder Head - Husqvarna TC 450 Workshop Manual

Cleaning of components

All component must be cleaned with petrol and dried with compressed air.
During this operation inflammable vapours burst out and metal particles may be violently ejected. Consequently, it is recom-
mended to work in a room free from bare flames or sparks and that the operator wears goggles.

Assemblies

For a good and efficient engine operation, it is essential that all assemblies are within the tolerances prescribed. In fact, a "close"
assembly causes seizures as soon as the moving members heat up; while a "wide" assembly causes vibrations which in addition to
being noisy accelerate the wear of the moving components.
ENGINE OVERHAULING

Cylinder head

Remove carbon deposits from the combustion chamber using a rounded
scraper.
Do not use a sharp tool to avoid valve seats and spark plug thread
damaging.
Check the machined surfaces of the cylinder head using a straight edge
and a feeler gauge taking readings at the points shown in the figure. If
the reading at any point is greater than the limit prescribed then regrind
the contact surface with the cylinder. Cylinder head distortion limit:
0.0019 in.
G.2 Part. N. 8000 H1344 (10-2009)