Stihl 4137 Series, Manual, Page: 46 / 58

45 Series 4137 Components - HT
:
Connect suction hose (2) of
vacuum pump 0000 850 3501 to
the fuel hose (1).
:
Close the vent screw (3) on the
pump.
:
Operate the lever (4) until the
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2
1
5
4
3
pressure gauge (5) shows a
vacuum of 0.2 bar.
This vacuum must gradually
disappear. If it remains constant, the
tank vent is faulty and must be
replaced.
The diaphragm pump draws fuel out
of the tank and into the carburetor
via the fuel hose. Any impurities
mixed with the fuel are retained by
the pickup body (filter). The fine
pores of the pickup body’s filter
eventually become clogged with
minute particles of dirt. This restricts
the passage of fuel and results in
fuel starvation.
In the event of trouble with the fuel
supply system, always check the
fuel tank and the pickup body first.
Clean the fuel tank if necessary,
b
9.7.
– Drain the fuel tank.
– Remove the rewind starter,
b
6.2
– Pull the fuel hoses off the elbow
connectors on the carburetor,
b
9.2.2
Dispose of fuel and lubricants
properly at approved disposal site.
Cleaning the fuel tank
:
Unscrew the filler cap (1) and
drain the tank.
– Pour a small amount of clean
gasoline into the tank and shake
the unit vigorously.
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– Open the tank again and drain it.
Dispose of fuel and lubricants
properly at approved disposal site.
9.6 Pickup Body 9.7 Fuel Tank/Fuel Hoses