Sierra 18-1236 Oil Drain Screw for OMC Cobra Drives

The Sierra 18-1236 is a replacement oil drain screw designed for OMC Sterndrive/Cobra drives and V6, 40-50hp outboards from 1989-1997. This drain screw replaces OEM part number 309243, providing a reliable aftermarket solution for lower unit maintenance.

Key Features:

• Manufactured to meet or exceed OEM requirements
• Essential component for routine gear lube changes and lower unit service
• Designed for OMC Cobra stern drives and select Johnson/Evinrude outboards
• Uses O-ring seal (Sierra part 18-4253-9, OEM 336982) for leak-free operation

Application:

• OMC Cobra Drives
• Johnson/Evinrude V-6 and 40-50HP outboards (1989-1997)

This drain screw is a critical wear item that should be inspected regularly and replaced if threads are damaged or if proper sealing cannot be achieved. Regular replacement during gear lube service intervals helps prevent costly lower unit damage from water intrusion.