It probably wasn't 4 ounces.
First wasn't very big by my standards, so I waited maybe 15 minutes and tried again (got a surprising amount the second time, didn't expect that much).
It was perfectly fine at the sperm bank, because I ejaculated beforehand the same day. If I go over a day, I start getting the yellow nasty stuff.
We have some of those kinds of sample cups in the department storeroom, and they have graduation marks on them. I'll try and verify it tomorrow, if I get the chance. Regardless, compared to the "average" amount of ejaculate of approximately 1-2 teaspoons, the amount you produce is extremely large. I know, from research, and some ex's that produced large loads, that if they didn;t get off for a day or two, that their cum was more yellowish. Basically, your body is used to producing huge amounts of semen, and stores it in the prostate---it is used to getting it emptied regularly, and it continues at a normal production level for you. The yellow is from "old cum", old being a relative term, but for you "old" is cum more than a day or two old. Since semen has a fair amount of diglycerides, I suspect that is where the "oily" texture is coming from---think what happens when you let oil and vinegar stand for awhile--they seperate. I suspect your semen, since you are used to producing so much, tends to break down a bit quicker than others. Note this is just an analytical guess based on your description. If you go a couple of days without ejaculating, do you develop a dull ache in your balls, or what feels like one? I am guessing you do. Drink more water, as stated, and reduce your intake of fats. If you don't want to ejaculate as often, then you have to retrain your body to not produce as much, which usually means abstaining from masturbation or sex for a fairly long period of time--like, weeks. Frankly, I don;t think it is worth it, and I bet your lovers really enjoy your prodigious volume. Try the water and fewer fatty substances for about a week, and see if that makes a difference.