Inspecting Fuel Tank And Tank Vent - Yamabiko ECHO SRM-420ES Service Manual

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4-3 Inspecting fuel tank and tank vent

C
D
E
FUEL SYSTEM
1. Remove air cleaner cover. Disconnect black fuel
line from carburetor and connect pressure tester
897803-30133 (A) to fuel line with joint pipe V186-
000510 (B).
B
A
2. Pinch tank vent line (C) with longnose pliers to
block air passage. And then apply 50 kPa (0.5 kgf/
cm
NOTE: Wrap the ends of longnose pliers with tape
(or cover with soft pipes) to protect tank vent line
from damage.
3. The pressure should not drop. If the pressure
drops, leakage may be occurring from fuel cap
gasket, fuel tank, fuel lines, tank vent line or fuel
line grommet. Inspect and replace them as re-
quired.
4. Release tank vent line. The pressure should
stay at or above 10 kPa (0.1 kgf/cm
pressure drops under 10 kPa (0.1 kgf/cm
psi), tank vent or tank vent line is defective.
NOTE: Tank vent prevents a vacuum from forming
in fuel tank when fuel in fuel tank is being con-
sumed. When pressure in fuel tank becomes too
high, tank vent releases the pressure.
5. Remove tank vent (D) from tank vent line and
connect pressure tester 91139 (E) or 91149.
6. Apply pressure approximately 50kPa (0.5 kgf/
cm
D
range of 10 - 40 kPa (0.1 - 0.4 kgf/cm
psi).
7. If it is not in the range, gently clean tank vent
with compressed air or replace with new one.
NOTE: Do not disassemble valves in tank vent as-
sembly. Damage to valves will occur.
8. Apply negative pressure 20 kPa (0.2 kgf/cm
psi).
9. Tank vent should pass air freely without holding
any pressure. If it dose not, replace tank vent with
one.
SRM-420ES, SRM-420TES
A
2
) (7 psi) of pressure.
2
) (7 psi), make sure the pressure is stable in
T410S, B410S
T410TS, B410TS
B
2
) (1.5 psi). If
2
) (1.5
2
) (1.4 - 6
2
) (3