Testing Cylinder Compression; Cleaning Cooling Air Passages - Echo CS-310 Service Manual

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8-1 Testing cylinder compression

4. If pressure is more than approx. 125% of standard compression pressure, inspect cylinder combustion
chamber and exhaust port, piston crown, and muffl er for carbon deposits.
NOTE: Compression pressure varies with volume of compression gauge tip occupying cylinder combus-
tion chamber. If gauge tip volume is considerably different from spark plug volume, it is recommended to
measure and note compression pressure of brand-new engines as standard pressure in advance.

8-2 Cleaning cooling air passages

ENGINE
NOTE: Test cylinder compression when engine is
cold.
1. Move ignition switch to STOP position. Then re-
move spark plug.
2. Install compression gauge 91037 (A) in spark
plug hole and tighten by hand. Pull starter several
times to stabilize reading on compression gauge.
A
3. If pressure is lower than approx. 75% of
standard compression pressure (Refer to "1-2
Technical data"), inspect cylinder bore, piston and
piston ring for wear or damage.
1 . R e m o v e c y l i n d e r c o v e r. R e m o v e s t a r t e r
assembly (Refer to "2-1 Disassembling starter as-
sembly").
Always wear eye protection when using
compressed air for cleaning. Otherwise,
eye damage can occur from fl ying particles.
A
2. Inspect cylinder cooling fins (A) for blockage
with dirt and/or saw dust. Clean them with wooden
or plastic stick or compressed air as required.
3. Install all removed parts.
WARNING DANGER
CS-310