I'm finally beginning to work on my 1984 gl1200, it has 42,000 miles ,has been sitting several years (inside) it has nice clean coolant, plugs look great, not wanting to rush things so I removed the Radiator, and timing covers, put only about 1/4 cup MM oil into the cyls. let sit for a couple of days, turning by hand (socket on crank bolt) the engine turns about 1/2 rev. and stops, no clunk like something hitting a valve or ?? just kind of slowly gets hard to turn . I didnt force it at all, should I take vale cover off to make sure no vale sticking open, then "if not" put some force behind it ? I'm thinking it has a "rust ring" around cyl.?? I know the carbs will need to come off, it sat with gas in the tank,and pet cock open.