1985 Johnson 25hp

So I'm new to the forum but have been browsing for years. After reading all the good info on here I've finally decided to do a little bit of work on a neglected but in great shape outboard my old man bought brand new in 1985. It's a 1985 Johnson 25hp. Today was the first time it came off of the boat in 30 some odd years and surprisingly the thing still fires up within 10 pulls. But the time has come where it's time to do the old 35hp conversion to waken up this old beast. I know you need the carb and intake but I'm not sure what years work for the conversion and if I can use the carb/manifold off of a remote steer model?
Once again it's a 1985 25hp Johnson tiller steer.
Thanks

Johny25 did a lot of research on this conversion and documented his results. Definitely a good read. Good luck.
https://www.tinboats.net/forum/viewtopic.php?f=4&t=23898

Yes it is very informative but I did not see any info on being able to use the carb and manifold from a remote steer outboard on a tiller control outboard.

Prerun said:

Yes it is very informative but I did not see any info on being able to use the carb and manifold from a remote steer outboard on a tiller control outboard.

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From which model and year?
You'll have to do a little leg work comparing the part numbers.
I like using boatsnet, but other sites may work as well.

Btw, welcome aboard!

For comparing and looking up part numbers, I have been using shop2 dot evinrude dot com

There will be a dropdown box in the top left corner.. pick Johnson and your year/model.

I'm having a hard time figuring out what year carbs/manifold i can use. No matter where I look in see different part numbers everywhere but nothing that cross references to a specific year..
Thanks in advance

Prerun said:

I'm having a hard time figuring out what year carbs/manifold i can use. No matter where I look in see different part numbers everywhere but nothing that cross references to a specific year..
Thanks in advance

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To answer your question if a remote carb and manifold will work the answer is yes. As to year I can't answer that, that is part of the work that goes into this conversion, the figuring part. I have converted a couple other brands but it has been a while and I couldn't remember now if my life depended on it what years were compatible.

I have seen the threads here on the conversions on the OMCs and at one time was going to convert a 25 myself but sold it before I got seriously into it.

Even if I could find part numbers It would help a lot but I don't know what part numbers correspond to the proper carb and manifold for the upgrade

Part numbers are pretty straightforward but if all else fails an omc dealer with a parts dept can be a lot of help if you find someone who knows their stuff.

That's the problem though, there not straight forward. within a time span of a few years there are multiple part numbers for 35hp carbs.

Prerun said:

That's the problem though, there not straight forward. within a time span of a few years there are multiple part numbers for 35hp carbs.

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Well when all else fails ask some of the salvage places/mechanics. Most times they know, some aren't going to tell you, and some aren't going to take time to tell you. But if you are truly serious that is how you find out.
I just did a search here and came up with 36 pages, here is one thread that may help. If not it is still informative.

https://www.forum.tinboats.net/viewtopic.php?f=4&t=23898&hilit=25+HP+conversion

Thanks for the link but I've researched that thread already. It's just the part numbers that are confusing for different years and models

Prerun said:

Thanks for the link but I've researched that thread already. It's just the part numbers that are confusing for different years and models

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Yes, reason being there are 30/35 HP carbs across a number of years that will work for your motor.
Both the butterfly choke and primer versions will work as well.

Edit : I replaced the manual primer carb with an older 35hp choke carb setup on my '88 30hp Johnson. Runs great.

Is the 30hp carb the same as the 35hp

Prerun said:

Is the 30hp carb the same as the 35hp

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They are equivalent. Note, no horse power gain in my application. I just preferred the
choke over the primer system.

Around 1985 the 35hp decals were replaced with 30hp decals. Same motors but they used a different way of measuring hp. So for all the expense involved you might gain 5 hp.