New to me 1975 25hp Johnson

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baseball_guy_99

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Sold my 9,9 w/15hp carb this morning...got $450 out of it...

Turned around and bought a 1975 25hp Johnson for $275. It's a little rough on the outside...but under the hood is clean.
 

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Those old Johnsons are some brute motors! Personally, I think it looks pretty good for being a '75.
 
All the old johnson motors I've seen were as tough as a chunk of steel and ran forever. That was some great wheeling and dealing to gain $175 and 10+ hp.
 
Alright guys...need a bit of help already haha.

I was taking the carb off to check it because it had sat for about 6 months...I unscrewed the wrong screw and now I can't get it back in the right position to work the choke...

If someone could get me a closeup picture of this...

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I can't figure it out :D
 
Never mind...I got it. Persistence pays off!

Snapped a few more pictures...
 

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Motor sounds solid. I didn't notice any water coming out of a tell tale hole. But I'm not positive that motor has one but I would think it would.
 
Nice! Those 20-25hp motors from late 60`s to early 70`s are my favorite as i`ve got 2 of them myself. Make sure when you run it in a bucket you have the water line above the pump( fill your bucket up another 8''-12'' of water) One of the best power to weight ratio motor you will ever find. Great job on the trade up =D>
 
It does not have a tell tale. If you notice when I walk around back there is water coming out about midway up the exhaust housing.

I'm gOinng to look into getting a barrel. That's the biggest container we had.
 
baseball_guy_99 said:
I'm gOinng to look into getting a barrel.

If you've got a crop duster or spraying service in your area, you might want to check with them. The ones around this area go through hundreds of heavy duty plastic barrels each year and they have to stack and store them until the recycle guy comes around each year. They can be had for the asking around here as they want them gone. And you can usually take your pick of 55 or 30 gal. The good part about the plastic is that you can cut and modify it to suit your needs with a jig saw and they make great test tanks that don't rust.
 
Well I took apart the lower unit and everything looks great! The previous owner must have changed the water pump and impeller because it looked new.

Put everything back together and fired the motor up.
https://s2.photobucket.com/albums/y32/d_rednour05/?action=view&current=IMG_0262.mp4

It idles great! Let it sit and idle for about 5 minutes...kicking out water the whole time. I checked the block a few times and it was warm but not hot. Let it run a little longer and I checked the block again...it was getting hot. It was still pumping water good so I checked the thermostat. Sure enough the thermostat is broke.

So I order a new thermostat, seal, and gasket.
 

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Good you caught it now before it overheated on the lake and fried something. You should be able to hold your finger on the head for 3-4 secs when up to operating temp before it burns your finger when its cooling correctly.
 
Wow that motor hardly kicks any water in the bucket...my 10 hp keeps it churning pretty steady.
 
Ultra, that's about how long I could hold it on there...but it just felt too hot.


I'd, I thought the same thing...it gets pretty crazy when I put it in gear though!
 

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