Merc 50 - Lower unit won't seat

[Astro Raills 2.0]

Hello, got a boat here for the first time in a few years. Replaced that water pump on the lower unit, and now can't get the lower unit to seat all the way onto the driveshaft housing. Both lower unit and motor are in forward gear.

The motor is a 1982.

I can get it to within 1/2 an inch or so of seating. If I turn the flywheel, the prop turns. I can also shift from forward to neutral and back again. But cannot get the whole thing to seat. Definitely do not want to force it.

When I had an '94 Evinrude, I just had to jiggle the flywheel to get everything to seat, not doing the trick here.

Any tips for a 2nd term rookie? Thx Peter

 

[Astro Raills 2.0]

And does it matter if the engine is tilted up or not? Currently have it tilted up. Wonder if that's putting an odd pressure on something?

 

[GA_Boater]

Sounds like the water tube is hanging you up. I find it easier to to put the motor vertical and use a thin screwdriver to position the water tube.

You do have the water tube hanging from the motor, don't you? Same try to plug it into the water pump outlet and stab it upwards - Very frustrating that way.

 

[Astro Raills 2.0]

The water tube was in place. Turns out that there's a rubber gasket in the lower unit for the exhasust pipe. I had taken this out and put it in upside down. Put it in the right way, and the lower unit seated properly.