1985 Johnson 25hp help

ermaclob

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So im pretty new to boating and there motors and am trying to get my first boat going. A Friend of mine sold me his old johnson engine for a good price. the problem im having with the engine is as follows. u pull start the engine and it will run on idell for about a 10 -20 sec but will kinda hiccup a few times and stall out you can even throttle it a bit before it shuts off. doing so will make it shut off faster.

from what my friend was telling me he thinks that its a carburetor issue. the engine has been sitting for about a year. he thinks it needs to be cleaned or something. playing with the needle valve seems to make it change a little :/

was wondering if this is a possible issue? how hard would it be to fix my self?

if its of any importance the motor has compression and are pretty equal on both spots.
 

jbjennings

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Re: 1985 Johnson 25hp help

Your problem does sound like a fuel issue, but...... First I would check spark and make sure you do it with a tester that will verify that the coil will put out enough voltage/current to jump at least a 1/4" air gap with a bright blue pop. They should be the same on both cylinders. Next, clean your carbs (not hard--just make sure you soak them good and blow out all the tiny passages. Use a new carb kit because old needles/seats are bad about giving problems, along with leaky gaskets causing vacuum leaks.
Replace all your fuel lines under the cowl, make sure the fuel in your tank is fresh and clean, and put in a new water pump impeller whether you think it needs it or not. A spark tester is less than $10 at most auto parts stores. Get the air gap kind, not the neon light kind.
JMO,
JBJ
 
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ermaclob

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Re: 1985 Johnson 25hp help

Your problem does sound like a fuel issue, but...... First I would check spark and make sure you do it with a tester that will verify that the coil will put out enough voltage/current to jump at least a 1/4" air gap with a bright blue pop. They should be the same on both cylinders. Next, clean your carbs (not hard--just make sure you soak them good and blow out all the tiny passages. Use a new carb kit because old needles/seats are bad about giving problems, along with leaky gaskets causing vacuum leaks.
Replace all your fuel lines under the cowl, make sure the fuel in your tank is fresh and clean, and put in a new water pump impeller whether you think it needs it or not. A spark tester is less than $10 at most auto parts stores. Get the air gap kind, not the neon light kind.
JMO,
JBJ

sounds like a plan. do you have any idea where i can get a service manual for the motor?

also for a carb repair kit? would this work part # 54


and where and what is the water pump impeller?

thanks
 
Last edited:

jbjennings

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Re: 1985 Johnson 25hp help

KenCook.com for an OEM manual. DOn't settle for less than an OEM.
THere's lots of online sites that have online parts diagrams, but I'm not sure about your kit you linked.

The water pump impeller is a rubber part that is found in your lower unit. It is found on the driveshaft and they go bad from sitting unused so that they don't pump water at idle well, and can dry rot and fail at high speeds causing your motor to overheat and score cylinders and pistons. It's not a hard job, and one easily accomplished with a manual. Basic tools are all you need and these are things you need to know how to do if you really want to get into boating and aren't wealthy. I'm almost positive iboats sells those manuals and carb kits.
BTW, never run your outboard out of water, even for a few seconds. The water pump impeller is always spinning, even when the motor is in neutral, and needs water to lubricate the rubber impeller which rubs against metal which lines the impeller housing. If your motor has a decal that says run the oil/fuel mix at a 100:1 ratio, ignore that label and run it 50:1. The 50:1 suggestion is based on a factory service bulletin--not me, BTW.
Hope this helps,
JBJ
 

oldboat1

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Re: 1985 Johnson 25hp help

good info. above. If you can provide a model number, should do that -- and can google the motor w/model number to see what hits you get, if you haven't tried that. Can be instructive.
 

ermaclob

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Re: 1985 Johnson 25hp help

good info. above. If you can provide a model number, should do that -- and can google the motor w/model number to see what hits you get, if you haven't tried that. Can be instructive.

model # says sj25rsw
 

ermaclob

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Re: 1985 Johnson 25hp help

Btw that KenCook.com web page is blank to me. dont know if anyone else is having that issue
 

oldboat1

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Re: 1985 Johnson 25hp help

well, there appears to be a google hit on that model number (Johnson sj25rsw). Appears to be a Brazilian motor(?) Try the search -- maybe gives you enough information to call BRP for more info? There was a similar issue/situation some time ago here, but don't recall what came of it, if anything.
 

ermaclob

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Re: 1985 Johnson 25hp help

I have been following this thread because I also have a 1985 Johnson 25HP. Your model number appears to be incomplete based on what is available at the link below on Page 2. Please verify.

http://shop.evinrude.com/media/document/ModelNumberReference.pdf

Bro, thats all i got. Its stamped USA tho :/ not south america or brazil

2014-03-03195901_zps6915d855.jpg
 

oldboat1

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Re: 1985 Johnson 25hp help

just nothin' to offer up here -- sorry. Still think a call to BRP might be helpful, though, for an explanation -- maybe some kind of cross reference that would help you get parts/manuals.
 

nwcove

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Re: 1985 Johnson 25hp help

heres what i come up with fwiw. 1985 motor as stated...... S=south america, J 25 = johnson 25 hp, RS=rope start, W=110 degree angle drive.
 

racerone

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Re: 1985 Johnson 25hp help

??????-----------110 degree angle drive on a 25 hp motor , never heard of such a thing.
 

ermaclob

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Re: 1985 Johnson 25hp help

heres what i come up with fwiw. 1985 motor as stated...... S=south america, J 25 = johnson 25 hp, RS=rope start, W=110 degree angle drive.

the W stands for commercial model i think.
 

nwcove

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Re: 1985 Johnson 25hp help

V = Special Gearcase
W = 110? Angle Drive - Rope Start <----------?
WM = Electric Commercial - Manual Tilt

copied and pasted ^. ( rs does show as a rope start commercial)?

maybe im reading the chart wrong.
 

ermaclob

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Re: 1985 Johnson 25hp help

V = Special Gearcase
W = 110? Angle Drive - Rope Start <----------?
WM = Electric Commercial - Manual Tilt

copied and pasted ^. ( rs does show as a rope start commercial)?

maybe im reading the chart wrong.

actually i think your right. i was looking at the 2000th chart
 
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