Echo PB-251, Руководство по обслуживанию

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PB-251
ENGINE
42
7-3 Checking muffler and exhaust port (continued)
3. Remove holders (B), gasket (A), and screen (C,
if present) from muffler.
4. Remove carbon deposits from screen, muffler,
and other component parts. If heavily deposited,
replace with new parts as required.
5. Reinstall muffler together with new gasket and
other removed parts.
7-4 Testing crankcase and cylinder sealings
1. Remove carburetor and muffler.
2. Close intake port and crankcase pulse passage
using pressure plug 897826-16131 (A) and pres-
sure plate 897827-16131 (B).
3. Close exhaust port with pressure plug 897826-
16131 (A) and install muffler.
4. Remove spark plug and install pressure connec-
tor 897835-16131 (C).
5. Connect pressure tester (D) to the connector and
apply approx. 0.2 kgf/cm
2
(3 psi) of pressure.
NOTE: Do not exceed 0.5 kgf/cm
2
(7 psi), damage
to oil seals will result.
6. Gauge should indicate constant pressure at mini-
mum of 0.2 kgf/cm
2
(3 psi).
NOTE: An air leak down rate of 0.05 kgf/cm
2
(1 psi)
per minute is acceptable until the minimum holding
pressure of 0.2 kgf/cm
2
(3 psi) is attained.
7. If the reading drops, use soapy water to locate
leakage. Leakage may occur from cylinder base,
crankcase seam, or oil seal.
8. Remove plugs from exhaust port and intake port
after this test, and reinstall all the removed parts in
place.
(C)
(A)
(B)
(C)
(D)
(A)
(B)