1977 Evinrude 6HP 6704M Water Pump

I,m new to outboard engine work and new to this forum. This motor has been sitting in a garage for probalby over 10 years without being run. I have the motor running, but not getting any water from the tell tail or from the exhaust tube. Smokes something terrible when I start it. I have fresh gas mixed at 50:1. I removed the lower unit and the impeller looks ghood as far as I can tell. Still soft and flexible, but I don't know what a good one should look like so I don't know. There is oil in the impeller housing though and I don't think there should be. Could my excessive smoking be caused by oil passing through the water cooling channel? I'm thinking I should replace the impeller, oil retainer and maybe the bearing housing gasket. I'd also like to replace the inlet water intate screen and plug, but how do you remove the old screen.

Definitely install a new impeller.-----Is the screen damaged ?

I can't tell without removing it, but what I can see does not look damaged, but may be clogged up. Any idea how to remove the plug so I can remove the screen?

When you pour water down the pump intake channel does it pour out the screen ?----------------Just pry out the plug.------clean / replace the screen.----------Drill / tap for suitable pipe plug.

I haven't tried putting water down the pump intake channel. I'll try that tonight. Thought of that this morning as well to see if water should be getting past there. Does haviong oil in the impeller housing seem right to you?

There should be no gear oil there.

Water goes down the pump intake channel and comes out the screen. I think the screen is slightly clogged, so I'll work on getting that out and cleaning or replacing. I pulled the thermostat and it is coroded and couldn't possibly be working. If it is stuck closed, I'd assume that this would prevent any water circulation?