# New to me 1975 25hp Johnson



## baseball_guy_99 (Jan 25, 2012)

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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## fool4fish1226 (Jan 25, 2012)

Nice =D> nothing a little paint can't take care of. Is it in running condition.


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## baseball_guy_99 (Jan 25, 2012)

It sure is.


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## fool4fish1226 (Jan 25, 2012)

Even better you made out well


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## Butthead (Jan 25, 2012)

Those old Johnsons are some brute motors! Personally, I think it looks pretty good for being a '75.


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## JMichael (Jan 25, 2012)

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.


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## crazymanme2 (Jan 26, 2012)

I have one of those & they are great running motors. =D>


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## baseball_guy_99 (Jan 26, 2012)

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...





I can't figure it out


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## baseball_guy_99 (Jan 26, 2012)

Never mind...I got it. Persistence pays off!

Snapped a few more pictures...


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## UtahBassKicker (Jan 26, 2012)

That thing looks almost new under the hood. Made some money and a HP upgrade. Well done!


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## baseball_guy_99 (Jan 26, 2012)

Here is a video of it running...


https://s2.photobucket.com/albums/y32/d_rednour05/?action=view&current=IMG_0256.mp4


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## JMichael (Jan 26, 2012)

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.


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## ultra353 (Jan 26, 2012)

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>


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## Mike Redmond (Jan 26, 2012)

Awright,purring just like a kitten with a bowl o warm milk


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## baseball_guy_99 (Jan 27, 2012)

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.


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## JMichael (Jan 27, 2012)

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.


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## baseball_guy_99 (Jan 30, 2012)

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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## ultra353 (Jan 30, 2012)

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.


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## Jdholmes (Jan 30, 2012)

Wow that motor hardly kicks any water in the bucket...my 10 hp keeps it churning pretty steady.


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## baseball_guy_99 (Jan 30, 2012)

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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## jonmac3569 (Feb 3, 2012)

bbguy,

I have the exact same motor. You can see my thread in my signature. I have went through several issues in the thread but a few more that are not in the thread so let me know if you have any issues. I don't know everything about the motor but there is a fair chance I have toyed around with it. About the only things I haven't messed with are the cylinders and and lower unit.

One thing that made a big difference in mine was changing the J4C plugs to J6C, hotter plug and ran much better. (thanks to a suggestion on this site) I had a thermostat that was failed open so it was running cold. Changed that and the plugs at the same time and running great now.


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## baseball_guy_99 (Feb 4, 2012)

Ya I was going to change the plugs. The ones that are in there now are NGKs.
I'm going to replace them with the champions. Thanks for the heads up on which ones to use.


Got the thermostat put back in last night. I'm going to fire it up this week and see how she runs.


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