1986+ Mercury 6/8/9.9/10/15HP 2-stroke Factory Service Manual, Page 235Get this manual

GEAR HOUSING
10Remove water pump base and shift shaft from housing11Remove gasket

- SealPump baseShift shaftGasket (discard)

• ATV
• Jet Ski
• Outboard Motors
• Personal Watercraft
• Snowmobiles
• Stern Drives