In order to check the level of oil in the RV-4, the RV-4 will require 13 and 17 head heads. The test is running as follows:
(1) Hole the cork of the filler hole (located on the side of the carton of the carton);
(2) Check the rubber sealing ring: if it is badly compressed, ragged or solidifying, it must be changed;
(3) Check the level of oil with a finger or with a screwdriver. The level must be 5 mm below the hole.
(4) If the oil is below acceptable oil, it must be provided with a syringe. The GL-4 oil and 75W-90 viscosity is filled in the box.
5) End the filler cap.