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L. MECHANICAL PARTS OF 4 STROKE
ENGINES
1. GENERAL
The engine block/assemblies supplied for the vertical shaft
and horizontal shaft engines are similar in construction
(apart from mounting differences). The disassembly and
inspection of these is therefore almost the same. (Fig 1).
2. COMPRESSION CHECK
Check compression by hand or with a compression
gauge, for compression details see table. If compression
is weak, check:
- spark plug threads
- cylinder head gasket for leaks
- valve seat condition
- cylinder, piston and rings
NOTE - If engine is fitted with compression release, it
is necessary to remove the cylinder head and check
components visually.
HEAD AND GASKET
If leaking occurs at cylinder head, remove and check for
distortion or damage to sparking plug threads, if necessary
replace the head using a new gasket.
NOTE - With the SIC compression tester checking can
be done without disassembling the cylinder head.
3. VALVES
After removal of the head visually check the valves and
seats. If removal is necessary remove breather assembly
and parts with special tool 88841012 (Fig 2) lift valve
spring. The securing cap may then be removed, the same
procedure applies to both valves. Withdraw the valves
and remove all carbon deposits from the seats and
cylinder. The valves may now be “lapped” in.
In case of badly burned or pitted seats it will be necessary
to re-cut the seats to an angle of 45 degrees using special
tool 26990002 and 26990001 (Fig 3).
Fig.1
Fig. 2
Fig. 3
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For Discount Tecumseh Engine Parts Call 606-678-9623 or 606-561-4983
