Testing Crankcase And Cylinder Sealing; Removing And Inspecting Cylinder - Yamabiko Echo SRM-2620ES Service Manual

SRM-2620ES, SRM-2620TES
T262XS, C262S
T262TXS, C262TS

6-4 Testing crankcase and cylinder sealing

A
B
G
F

6-5 Removing and inspecting cylinder

A
ENGINE
1. Remove cylinder cover, muffl er, air cleaner cov-
er and carburetor.
2. Close intake port and crankcase pulse passage
using pressure rubber plug 897826-16131 (A) and
Bellows holder (B).
3. Close exhaust port with pressure rubber plug
897826-16131 (C) and muffl er (D).
4. Remove spark plug and install pressure
C
connector A131-000160 (E) to spark plug hole.
D
5. Connect pressure tester 91149 (F) to pipe (G).
6. Apply pressure approx. 50 kPa (0.5 kgf/cm2) (7.3
psi) by pressure tester and leave for 30 seconds.
NOTE: Do not exceed 0.05 MPa(0.5 kgf/cm
psi), or damage to seal will result.
7. Gauge should indicate constant pressure at a
minimum of 0.05 MPa(0.5 kgf/cm
E
NOTE: Leak less than the value of 0.005 MPa(0.05
kgf/cm
8. If the reading constantly drops, use soapy wa-
ter to locate leakage. Leakage may occur from the
cylinder base, crankcase seal, or oil seal.
9. Then, apply negative pressure approx. 30 kPa (0.3 kgf/
cm2) (4.4 psi) by pressure tester and leave for 30 seconds.
10. If the reading drops, leakage may occur from
oil seal. Inspect oil seal for damage or wear.
11. Remove plugs from exhaust port and intake
port after this inspection, and reinstall all the re-
moved parts.
1. Remove cylinder from engine.
NOTE: Cylinder can be removed together with
ignition coil (A), bellows holder (B) and intake bel-
lows (C).
B
NOTE: Gently tap cylinder head at carburetor side
and muffl er side with plastic hammer, if it is diffi cult
to remove.
2. Inspect cylinder combustion chamber. Clean it
C
with a wooden scraper if carbon is deposited.
NOTE: Never use metal scraper in cylinder com-
bustion chamber to avoid damage.
3. Replace cylinder with new one if plating is worn,
peeled away or scored, exposing cylinder base
metal.
2
)(1 psi) per minute is allowed.
45
2
)(7
2
)(7 psi).