Impulse Signal Present - Stihl MS 18 Servise Manual

25. Impulse Signal Present

Most two-stroke engines have a
passageway between the
crankcase and the fuel pump side of
the carburetor to cause the fuel
pump diaphragm to flex back and
forth with the pressure/vacuum that
is created by the piston moving up
and down
It is rare that there is no impulse
signal, but always verify that it is
present because no impulse signal
will cause a hard to diagnose,
unusual running behavior that will
appear to be carburetor related
© STIHL Inc., Virginia Beach, VA 2013
25. Impulse Signal Present
For the 1130 saw, remove the white plastic sealing ring, use
the tapered adapter and connect the tester to the impulse port
By hand, rotate the flywheel back and forth and the needle on
the gauge should bounce back and forth indicating the
impulse signal is present
© STIHL Inc., Virginia Beach, VA 2013
US/STR
US/STR
For this blower engine the
impulse signal comes out
through the flange here:
confidential
confidential
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