McGard Outboard Motor Lock For Yamaha/Honda M12 x 1.25 Thread Size. McGard outboard motor locks are designed to lock the bolt that holds the outboard onto the transom of the boat. Simply replace one of the mounting nuts with a McGard locking nut. These outboard motor locks are fully machined from high quality stainless steel and are through-hardened. A free-spinning collar turns if attacked by gripping tools. Fits the following outboard motors: Yamaha 40 hp and larger (2 stroke); Yamaha 30 hp and larger (4 stroke); Honda 40 hp and larger; Suzuki 25-140 hp (2005 and newer). Features of McGard 74037 Outboard Motor Lock For Yamaha/Honda M12 x 1.25 Thread Size Best protection available against costly outboard motor theft Designed to lock the bolt that holds the outboard onto the transom of the boat simply replace one of the mounting nuts with a McGard locking nut Fully machined from high quality stainless steel and are through-hardened See long description for compatibility Thread Size: M12 x 1.25; Hex Size: 5/8; Overall Length: 0.750 Package Contents: McGard 74037 Outboard Motor Lock For Yamaha/Honda M12 x 1.25 Thread Size McGard 74037: Outboard Motor Lock For Yamaha/Honda M12 x 1.25 Thread Size