Oil Pressure Switch (Optional); Testing Oil Pressure - Briggs & Stratton Twin Cylinder L-Head Repair Manual

Oil Pressure Switch (Optional)

A 1/8" NPTF plug in the oil filter adapter can be
removed to install an optional oil pressure switch.
When the oil pressure drops below approximately 5
PSI (.35 Bar), the switch may be used to activate a
warning device and/or stop the engine, Fig. 35. The
warning device and all wiring is supplied by the
equipment manufacturer.
Remove pressure switch for testing. Connect one
continuity tester lead to the switch terminal and the
other tester lead to the metal body of the switch,
Fig. 36. The tester should indicate continuity when no
pressure is applied to the switch. The switch should
open (no continuity) when approximately 4.5 PSI (0.3
Bar) is applied. Replace the switch if test results are not
to specification.

Testing Oil Pressure

1. Oil level must be between the LOW and FULL
mark on dipstick. If oil level is low, check for leaks
and add to FULL mark.
2. Remove pressure switch or 1/8" NPTF plug in oil
filter adapter.
3. Install oil pressure gauge, Fig. 37.
4. Start and run engine for approximately 5 minutes.
5. Check oil pressure at 3000 RPM.
Oil Pressure @ 70° F (21° C): 10-50 psi
(0.7-3.5 Bar)
See chart below for troubleshooting guide.
Low Oil Pressure
Engine RPM Too Low
Wrong Viscosity or Diluted Oil
Low Oil Level
Broken Pressure Relief Spring
Missing Pressure Relief Plunger
Worn Bearings
Damaged Or Defective Oil Pump
12
8
Fig. 35 – Oil Pressure Switch
Fig. 36 – Checking Pressure Switch
Fig. 37 – Checking Oil Pressure (Typical)
High Oil Pressure
Wrong Viscosity Oil
Plugged Oil Galleries
Stuck Pressure Relief Plunger