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CHAPTER 5 The Two-Stroke Cycle Engine
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is often installed in front of a pleated paper fil-
ter to stop large contaminants before they enter
the pleated filter.
A flocked air filter uses a screen structure cov-
ered with hair-like fibers, called flocking, that
allow air to flow through the filter but trap any
contaminants. Figure 5-33 shows a close-up of
the fibers on a flocked filter. Another name for
this type of air filter is fleece air filter.
The felt-type filter uses a dense layer of porous
fibers to allow air to pass through to the carbu-
retor. The filter fits tightly into the filter housing
to seal the housing. Figure 5-34 shows a felt-
type filter tight in the housing.
Fuel Tank
The fuel tank is the fuel storage and supply res-
ervoir for the two-stroke engine. The fuel tank
holds the gasoline premixed with the correct
two-stroke engine oil. The tank and its related
components must meet the EPA Evaporative
Emission Standards.
Components of the fuel tank are:
• Fuel tank.
• Fuel tank lid.
• Fuel tank vent.
• Fuel filter.
• Fuel lines.
Fuel Tank
The fuel tank is typically a separate molded plas-
tic container bolted onto the engine, Figure 5-35.
On the outside of the tank is the fuel tank lid,
vent, and fuel lines. On the inside of the tank is
the fuel filter, which is connected to the carbure-
tor through the inlet fuel line. The fuel tank vent
is located near the carburetor compartment.
Although most fuel tanks are separate con-
tainers, some two-stroke engines integrate the
fuel tank into the engine housing. For example,
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Figure 5-33. A flocked air filter has hair-like fibers
that trap contaminants from the air that passes
through the filter.
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Figure 5-34. A felt-type filter fits tightly into the
filter housing. The fiber material is porous enough
to allow air to move through the filter but fine
enough to trap contaminants.
Fuel tank vent Inlet fuel line
Fuel tank lid Fuel tank Return fuel line
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Figure 5-35. The fuel tank is made of molded
plastic. On the outside of the tank are the fuel
line(s), tank vent, and tank lid. Inside the tank is
the fuel filter.