There's a cover plate on the port side of the exhaust housing, near the bottom, held on by 2 screws. Take that off to access the shift rod connector. Disconnect the lower shift rod from the upper.
6 bolts hold the gearcase to the exhaust housing, take those out %26amp; pull the lower unit off. There's an o-ring on the drive near the splines -- that needs to be on there.
3 hex-head screws hold the pump housing in place. Pull it off over the drive shaft. Slide the impeller drive pin out %26amp; remove the impeller.
Remove the impeller base plate. If the housing %26amp; base aren't scratched or scored they can be reused.
Slide the new base plate over the drive shaft, followed by the new impeller. Insert the drive pin through the impeller %26amp; drive shaft.
Smear a dab of your trailer axle grease inside the housing, and slide the housing down over the impeller.
Using only your hand, turn the drive shaft clockwise while pushing housing down over the impeller. Don't use any kind of tool on the drive shaft splines.
Use molly lube on the driveshaft splines.
Use 3m #847 on the joint between lower unit and exhaust housing (permatex #2 is okay, just messier to apply %26amp; harder to clean off there next time).
Use OMC gasket sealant (or some kind of anti-sieze) on the threads of all the retaining bolts or else corrosion will freeze 'em in place.
How to change a water pump on a 1969 33 HP Johnsom Outboard?
I had a 1970 40HP, the water pump change was similar to newer outboards, drop the lower unit, replace the impeller and wear plate, and the housing if its damaged. Be careful of the wires coming down for the shift control if its electric shift, don't just yank the the lower unit off. A repair manual will give you more detail, its been a while since i changed it.
