Old karate\kung fu movie???? 80's flick?

Movie was on TV early 80's. Several times. I was young. To my best recollection, a guy owes a debt? and travels around to regroup a bunch of his old friends(about 5--maybe Army or POW's) and they all meet in on an oil rig field and compete against a group of "evil--doers" to fight. There's about 5 individual fights where they fight until the other is unconscious in the middle of nowhere. I'm pretty sure one fight involves a big African American man who knows little karate and know there is one fight that involves two women. Bad acting and bad martial arts involved. Just remember I loved it as a kid. This movie has been stuck in my head for years!! I know the YA group can help me! I've searched IMBD to no avail!