Re: No Reverse after water pump change on alpha one lower unit
To answer your earlier question, the shift should move easily when the drive is off the boat. If it's stiff it will need addressing.
In your picture it appears that the shift shaft coupler "shoe" isn't straight. That's the inverted u shaped connector that's supposed to slide onto the drive unit coupler "foot". It's on the bellhousing which the drive attaches to. If you or the previous owner shoved too hard with the shift couplers imperfectly aligned, it may have caused the shift shaft to bend.
With the drive off the boat shift (the drive) with the lower unit shift coupler "foot". It pivots between straight ahead, call it 6 oclock, for forward, and held counterclockwise at around 4 oclock for reverse, with neutral right between the two. If you hold the shift foot on the drive in a clockwise direction it should stop at 6 oclock. If it stops elsewhere, like maybe 7 or 8 oclock, you are on the wrong spline. To fix that you need to split the case and reset the foot on the lower shaft.
"OK. I dropped the lower unit, turned shift shaft CW, moved prop CCW till it stopped, and used bungee cord to hold into position. Put it all back together. The gear shift was in full forward position during all of this work. I tried to pull gear shift back to neutral, and it stops just short. also, when turning the prop it obviously not correct as it is not smooth and makes small clunking noise."
This is all OK, once you take off the bungee it will slip out of forward, the clunking isn't an issue either. Don't sweat that right now.
Once you can feel it shift you can use the prop to assure gears are engaged. When in reverse it will clack and might slip if you turn the prop counterclockwise, but it will hold when you turn the prop clockwise. In forward it will slip CW and hold CCW. Probably will ratchet a bit if you turn it CW while in forward. That's normal with the engine off.
You already did a good install, don't quit now. Once you have the shifter, cable and boat parts working put the drive in forward and bungee the prop CCW to hold it. This holds forward, and importantly, it keeps the coupler shoe straight ahead so you can install the drive.
When things are correct the couplers (shoe and foot) slip together as the drive is put on the boat.
But if that shift shaft isn't straight you might need to deal with it. If it's crooked it might be causing part of your shift bind. If you can have someone shift it at the control while you watch the bellhousing side of the coupler (the shift shoe) it might tell you.
Move the shift yourself too while the drive is off the boat. It will be good to know how much resistance is in there before you put the drive on. As I said at the top if it's not smooth that will need addressing.
Then, once you put the drive on, remove the bungee, wiggle the prop a bit to allow the gears to go slack, and shift to neutral. Try forward, neutral and reverse without running the motor. At each position make sure that the prop does the right thing.
In forward it won't turn counterclockwise.
In neutral it will turn freely.
In reverse it won't turn clockwise.
Hope this helps.