machine has set all winter i put dry gas in it hope that's the problem new spark plug but its running rich plug is black any ideas of what's problem? Haven't run it since I put dry gas in it.
Just wear on the tappets, I think. Or, depending on the engine, the buckets used for shimming. Some oils protect better than others; see the "best oil" threads and search "zinc".So what causes the valves to get out of time? Chain tensioner or broken chain guides? Its only 5 years old.
John