I saw this fix somewhere on the net several years ago, but I can no longer find it, so I took some pictures and wrote up a tech note.  My apologies to who ever came up with this idea, as credit where credit is due.  I believe that this is the same modification that Sabre Force performs for $$$, but I'm not sure.  It might take 30 minutes to do the first time and 15 minutes the next time.  It cuts down the amount of oil blown out by 80-90%.

Yorks are great compressors, but they were designed as air conditioning compressors and they normally pump a lot of oil out of their discharge port no matter what orientation they are mounted in.  It only takes a few minutes to modify the compressor so that is doesn't pump oil out.  The York is designed to pump oil to the seal via a loop using pressure in the crankcase to deliver oil to the seal and then to the suction inlet port.  You don't really need or want this oiling system when you are using the York as an air compressor.  It is the oil entering the suction port that is responsible for a lot of the oil that blows out of the compressor.

In order to plug this oil port, you need to remove the front seal from the compressor.  Remove the pulley and the magnetic clutch coil.  Then remove the 6 - 1/4 inch hex head screws from the seal retainer, remove the retainer and seal.  Check the compressor manual if you are not familiar with these operations.  The manual can be downloaded from:
 York compressor service manuals
The oil hole is 5/32 inch in diameter.  The pump shown in the picture is a Right side suction model.  If you have a Left side suction model, the hole will be on the left.  Cover the bearing with several layers of towels.  Plug the hole with a wad of paper towel shoved about 1 inch into the hole to keep metal chips out of the suction port.  Drill and tap with a 10-32 thread tap.  You are supposed to use a #21 drill with the 10-32 tap, but the 5/32 hole is so close that you don't really need to drill it out.  Carefully blow out the metal chips and cover the outlet port and blow compressed air into the inlet port to blow the paper towel plug out of the oiling hole along with any chips.  Brush out any remaining chips and then remove the towels.  Put a drop of blue or red locktite on a 10-32 x 3/8 plug or set screw and tighten it into the threaded hole.  Reassemble the seal, seal retainer, clutch and pulley and you are done.  Cost:  Tap $2.25, plug $0.15