Re: how on 1967 lower install
If you miss, you could bend or break the water tube, which means no water is getting pumped up into the engine. You'd be able to see that no water is coming out of the exhaust/water port. Then your engine would get hot and would blow the engine hot horn (if you have one), or if not, your engine would sieze if you didn't kill it.
It's hard to miss though, like everyone's saying. Here's some pics of my 1971 Johnson 9.5 HP. Not sure what size motor you have. In the first pic, see the arrow pointing to the water tube grommet? In the second picture, you can just see the water tube to the right of the drive shaft housing and just behind and to the left of the shift rod coupler. When you are reconnecting the lower unit you can look up at the water tube to make sure it goes into the water tube grommet on the water pump housing. Not hard, just be careful, and make sure you have the water tube grommet and drive shaft greased. Should also have a new o-ring on the upper drive shaft, if it has one.
