Section 5 Evaporative System (Evap) - ZONGSHEN ZS125-86 Service Manual

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Table Of Contents

Table of Contents

1. Working Principles of Evaporative System

Attach a carbon tank and close the fuel tank. The fuel vapor in the fuel tank can only be connected to

the atmosphere through the carbon tank. When the vehicle is at rest, the fuel vapor in the fuel tank enters

the carbon tank through the absorption mouth, and is adsorbed in the activated carbon in the carbon tank.

The desorption mouth of the carbon tank is installed on the intake pipe. When the vehicle is running, the

negative pressure in the connecting tube sends the fuel vapor adsorbed in the activated carbon of carbon

tank back to the engine via the carbon tank solenoid valve. Thus the pollution is reduced.

State Ⅲ Emission and Fuel Evaporation Schematic Diagram

A c t i v e c a r b o n

absorb oil vapor

to avoid emission

to the air

F u e l

tank

When a large amount of incompletely combusted mixed gas flows into the hot catalytic converter, it

may appear a re-combustion phenomenon, and lead to the catalyst converter being overheated in a way to

leave the catalytic converter invalid. To prevent this phenomenon and any other damage, please note the

following matters:

[1.]Only unleaded gasoline (#90 or #93 unleaded gasoline) can be used. The use of leaded gasoline

will cause the catalyst converter to fail.

[2.]When the motorcycle is running, do not turn off the master switch or slide the motorcycle in zero

position state taxi, to avoid the generation of a large amount of incompletely combusted mixed gas.

[3.]If the ignition or combustion system is not working properly, it will also cause the catalyst converter

to overheat.

[4.]After the motorcycle runs for a while, be careful that the exhaust pipe surface will become very hot.

[5.]When refueling, do not spill or overflow the gasoline on the exhaust pipe (high-temperature exhaust

pipe contacting with gasoline may be cause a burning).

Warning

Try to avoid dumping the vehicle. It results in fuel leakage from the fuel tank and causes the carbon

tank to fail.

Ensure the firm pipe connections of the fuel evaporation system, to prevent pipes from dropping out,

which may result in the direct discharge of fuel vapor into the atmosphere.

Do not adjust the carburetor at will.