The Mercury Service Tool is easy way to remove or install starter ratchet nut. Not everyone has access to the right stuff. The lip on top of the flywheel makes hex on bottom of ratchet shielded. The rough and ready solution is to pad the jaws of pipe wrench and carefully apply best estimate of proper torque.
I believe reproductions of the tool were available at one time. Those with skills, patience and access to a milling machine could make a passable copy of the tool.
Louis
w
tu
