1989 Harley Sportster 1200 engine won't turn over with Spark plugs in. Spins freely w/o plugs.?

I'd say Theharleyfixer is right on the money.Don't do as the Roger said and start taking things apart just yet.It takes much more torque from the starter to turn an engine over that has compression.The battery(and the connections) is the first place to start checking.Next would be the starter.