Check Air Intake Restriction

Remove cap on air cleaner test port and install Adapter (5650) and Pressure Test Kit (014-00761) to fuel supply pump inlet. See Figure . Run engine at 3300 RPM, with no load. Record restriction reading. Restriction should not exceed 25" of H2O. If reading is more than 2" of H2O but less than 25" of H2O, remove adapter. Install cap on air cleaner port and go to next test. If reading is 25" of H2O or greater, replace air filter element and check intake system for blockage. Repeat this test. If reading is less than 2" of H2O, correct restriction in fitting on air cleaner test port and repeat this test.