Recently purchased an 873 with 900 hours, stored inside and runs great. The issue is that it goes through engine oil at a rate of 1 quart in four hours. There is some lite "blueish" smoke out the exhaust but nothing seems excessive. There is also an oil leak of unkown origin that leaves a spot on the floor overnight but doesn't look excessive. I've read that it could be valve guides or stuck rings. I have not checked compression - it does start right up even in the cold (-8 F last week). Runs strong and works good. It's just alarming how much oil it uses.