Hello. I picked up 2 parts motors, 1995 70 hp forces over the weekend. One of the motors was purchased new by seller, who admits he used quicksilver oil, mixed correctly for its life. Motor did well for years, but eventually lost power. I pulled head just to peek at it, and top cylinder seems to have a damaged top ring land (actually looks like ring broke piston in a small area. What causes this? The second motor I believe also suffered a similar fate. It seems that Ive seen a fair amount of this on forum pictures.