I have a C-85 w ~1550 hrs ttsn (low TT) & "fresh o'haul" but never run from 25 years ago. It is not corroded in the cylinders and it was stored in a dry climate and area. I added a F & M full flow oil filter.
I started it first time w 40 weight oil about May 25th & had a little trouble getting oil pressure. I flooded the line to the oil gage & then things seemed OK. I ran it about 30 minutes on the ground.
Now 3 months later I'm almost ready to fly it in my J-4A, but I can't get any oil pressure again. I tried to back flush it thru the oil pressure gage restrictor w 40 weight oil from an oil can, and later from a small hydraulic pump, but so far no luck on the gage. My last run was ~ 30 seconds without any sign of pressure, so I tore off the cowl & reconnected the small pump to one of the oil galleries via the 1/2" npt port in the front of the engine.
Now I get 20 psi gage indication with perhaps 1/2 gal/min leakage flow back thru the engine, pump etc of 40 weight oil - all at ~75 degF.
Q - Have any one else experienced this? If so, how much oil did it take to prime the pump via the restrictor? How long between need for repriming? The restrictor is open.
I'm thinking that I probably have it primed now, but for how long is questionable. If necessary I'm thinkiing of using a small weed sprayer to force oil thru the restrictor so that I get a known quantity of oil into the engine.