R ovary cyst 4.2x3.8x3.6 CM left 2.5cm had cysts in past. Had partial hyst. At 27 endometriosis pain. Fam. Hist. Ovary can. Now 36 should I have ovaries removed.?

See a doctor. Talk with a good gynecologist in person, it's unfair to you to answer this online imho.
Tough question. If you have a simple cyst and are not having pain, then you should just follow this cyst with another ultrasound in 6 weeks. If it looks like an endometrioma, you might consider just removing that ovary. A robotic cystectomy may only require a two wk recover. I would not recommend putting yourself into menopause at 36 unless you are in alot of pain.