Need help finding info on 20hp Johnson

[Streaker]

I have an old 20 hp Johnson without the serial number plate on the transom. I searched the net and have the numbers off the freeze plug. Will these be of any help for someone that is knowledgeable about these things to tell me what yr it is and what manual I need to order for it.
The numbers are: 25R75B
E4226079
Thanx for any help you can give.

 

[Ouachita]

https://www.boats.net/parts/search/BRP/JOHNSON/1975/25R75B%201975/parts.html

This is the link I got pasting 25R75B into google. Sure it isn't a 25hp?

 

[Streaker]

Now I just feel stoopid!! LOL
Thanx for the help.
To answer your question No I'm not sure its not a 25 but it was sold as a 20 and has a 20 on the engine cowl but we all know how that goes.

 

[bassboy1]

https://www.boats.net/parts/search/BRP/JOHNSON/1975/25R75B%201975/parts.html

This is the link I got pasting 25R75B into google. Sure it isn't a 25hp?

Yep. That's correct.

 

[Streaker]

Well it looks like I have a 25 instead of a 20. Its going on a Lowe 1440 thats only rated for a 20. OMG I'm going to have to be very careful.
I just bought it for $225. I have to admit I broke a cardinal sin and didn't do a compression check. I did run it though and it runs good and even idles farely well for a 2 stroke. I have a friend who's dad works on boat motors so I'll probably have him go through it and check everything out. Wish me luck.

 

[CarlF]

What does it say on the cowling? Should have HP stickers on it.
I can tell from experience, a 25 will flat out make that hull fly.
I ran a 25 on mine for awhile during duck season the first year I had it.
The 9.9 I had wasnt cutting it so a buddy lent me his 25.
With me, a 250 lb partner, dog and lot more duck hunting gear than the boat is rated for, it would jump up on plane and scoot along at about 21.
Never clocked it with a "normal" load but I am sure I was doing over 25.
The next year I purchased my 18 Nissan and didnt run the 25 on it anymore.
Our state also passed a "no-over-hp" law that next year.

 

[Streaker]

Its got a 20 hp sticker on the cowl. Thats why I thought it was a 20 hp and the fact that the guy that sold it too me told me it was a 20.
I plan on cleaning it up and going thru it real goo and repainting it but due to the fact that my transom says max hp. 20 then I'm going to put the 20 stickers right back on the cowl.