johnson 7.5 hp squealing noise and some smoke

I was on my way back to the dock when my older (maybe 50's or early 60's)Johnson 7.5hp Sea Horse started to make a squealing noise and smoked when it did squeal. It happened about every 10 sec and then got started to get worse before I shut it down. The fuel was mixed 1/2 pint marine 2 cycle oil to one gallon. The plugs looked good, and it seems to still have good compression. I am a certified ASE auto mechanic so I am pretty good with engines and internals but I am not with the drive of the outboards. I only had maybe 4 Oz of hypoid oil in prop gear when I drained it and it was a light-light tan color but I'm not sure it was mixing with water because there was so little oil that came out. Maybe my water pump has gone bad or some bushings or bearings? When I put it in gear I can turn the engine over with the prop by hand, so I don't think it is totally screwed up yet but I need some input. Should I check the pump, drive. What should I take apart first. Thanks ahead of thime

Re: johnson 7.5 hp squealing noise and some smoke

Post the model number, 50's and 60's are way different.

Re: johnson 7.5 hp squealing noise and some smoke

And where was the smoke coming out?

Re: johnson 7.5 hp squealing noise and some smoke

I found out the engine heated up really quick while running it in the trash can of water. Threre was no water peeing out of the top. I"m sure it needs a water pump. The compression was 75 psi, is that good? The model number is 1637569. How involved is a water pump replacement and can you still get them? Do youi know of any sites that will assist me in pulling the lower half apart? Thanks in advance

Re: johnson 7.5 hp squealing noise and some smoke

Yes you can get impellers, compression looks ok (should run) it depends on what year and that isn't a model #. The model number should be listed on the transom clamp on a tag, that looks more like a serial number. If it's a 50's 7.5 the powerhead has to come off, then the shift rod nut is removed under the powerhead, 4 bolts at the gearcase and it drops, pump housing is at the top of the gearcase.