1985 Johnson 25hp lower unit question

[Blake0912]

Hi guys I just picked up a small 14ft aluminum Mirro craft that has a 1985 25 horse johnson on it and the lower unit on it looks like its older than an 85 to me? But the title says 1985 and matches the serial number. Maybe I'm just crazy but i swear it looks like something from the 70's.
Here is the model and serial number along with some pics. Thanks for your help.

Mod#- J25RWCO5
Ser# E6080925

I used the INTRODUCES method to verify that it was an 85 powerhead/casting at least and I'm pretty sure it is an commercial engine.
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[mark1961]

Re: 1985 Johnson 25hp lower unit question

Yep, its a commercial model and the lower units on the 25hp were exactly like that from the factory......

http://rides.webshots.com/photo/2246839970101354590jMNIed

 

[Blake0912]

Re: 1985 Johnson 25hp lower unit question

Thanks for the response i feel better now that i did not get screwed lol. Anyways is changing the water pump with these older style LU the same as the more modern style LU? Also how do I go about flushing it, is there a way around having to use a bucket/55 gal drum

 

[mark1961]

Re: 1985 Johnson 25hp lower unit question

Thanks for the response i feel better now that i did not get screwed lol. Anyways is changing the water pump with these older style LU the same as the more modern style LU? Also how do I go about flushing it, is there a way around having to use a bucket/55 gal drum

That style of lower unit was used up to the end of 1984 on recreational models as well, obviously longer on commercial versions. Same basic operation to change the water pump as a thru hub exhaust model, shift rod is probably released in a different way though, they would use different water pump kits also.....there are adapters made for hose flushing those lowers but i find them too pricey for what they are......http://www.sschapterpsa.com/ramblings/flushing_outboard_motors.htm

I have an Evinrude 1979 commercial 9hp auxillary (kicker) and barrel flush mine......just be certain you have the pump completely submerged......cant go wrong.

 

[Haffiman]

Re: 1985 Johnson 25hp lower unit question

Look for a oval cover plate with 2 screws on the side of the leg. Behind is the shift rod coupler. Completely remove the lower screw and the gearbox may be pulled down.
As a side comment, your engine seems to be mounted far to low on the transom. Normally the ventilation plate should be about 1" below bottom. Too deep and you get a lot of spray and loose speed. Buy a small drum to use when flushing, far better that any muffs!!!
TEMPO used to make a flusher that could be used on your engine, however I do not recommend it!

 

[Blake0912]

Re: 1985 Johnson 25hp lower unit question

The boat actually came with one of thous flusher it was under a seat and i did not see it, but its all rusty and looks like a POS in my openion i will just use the barrel, i mainly use in freshwater so not a big deal. So your saying to release the shift rod linkage it is actually located on the side of the leg? instead of behind the carb like on say my 1988 90hp johnson? And Haffiman I do not think it is mounted to low because it cannot go any higher then it is not it is already sitting on top of the transom and has been that way since the 80's seemed like it ran fine to me when I took it out. On a side not i did try to run it in a barrel yesterday afternoon so it kinda scared me, then i decided to take it to the lake and bam was pumping water..did I not have enough water in the barrel? it was about 3in over captivation plate. Thanks

 

[mark1961]

Re: 1985 Johnson 25hp lower unit question

On a side not i did try to run it in a barrel yesterday afternoon so it kinda scared me, then i decided to take it to the lake and bam was pumping water..did I not have enough water in the barrel? it was about 3in over captivation plate. Thanks

3 inches over the cav plate would not submerge the pump.....the bulge where the top of the lower unit and the exhaust housing meet is where the pump is located.....be sure to have the water level above there next time, fingers crossed you didnt cook the impeller first time round.

 

[Blake0912]

Re: 1985 Johnson 25hp lower unit question

I only let it run for about 10 seconds but it could of messed it up, i was going to replace the impeller anyway. Now when i order the part is there a special number i need to use since it is the older style LU?

 

[Haffiman]

Re: 1985 Johnson 25hp lower unit question

Here:
http://www.marineengine.com/parts/j...5RWLCOS&manufacturer=Johnson&section=Gearcase
You may get the impeller from multiple places, even this site and the part number should be the same.