I've recently inherited a 1998 volvo penta 5.0gi. It has been sitting for 10 years. Before changing fluids and turning the key i have done some research and seen some have put mmo in the cylinders to soak and free any rings that may be stuck. Anyone have any experience or input on doing this? Also... How do i clear the oil out of the cylinders after soaking. I know i can just turn the key with the plugs out but do i ground the plug wires? Leave the plugs in the wires? Thanks in advance.