Nilfisk-Advance 21KB Service Manual page 21

Service Manual – PBU Propane Floor Burnisher
8. Use a sturdy, clean, flat object to partially
block the air intake. (NOT YOUR HAND.)
9. Note the multimeter reading while the air
intake is restricted at high idle.
10. With a tuned engine and properly adjusted LP
regulator, an oxygen sensor should produce
.9 VDC or more when the engine is forced to
run rich and below .2 VDC when the engine is
forced to run lean. If the oxygen sensor does
not produce these VDC values when tested, it
should be replaced.
Figure 15 Partially Blocked Air Intake
Electrical System 21