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1975 Johnson 6Hp Gear Oil issue.

MassBoater

New member
I bought a 1975 6Hp Johnson outboard for my 14 ft aluminum v hull to get around small lakes. Paid 200 dollars and it runs great. I went through it cleaned it up, changed spark plugs and it ran on the first pull in a barrel. Went to change the gear oil and it had some water in it and wasn’t draining well and was pretty low. I pumped some new Johnson gear oil to get it to run out and let it sit for a day. Went to my local marina and purchased new gaskets for it and filled the gear oil. Ran it on the water twice and it ran great no issues. Went to drain the gear oil to see the condition of it and it was milky again. What should I replace next?
 

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Model # of the motor ?----I would say the easiest is to install a seal kit.-----Inspect the bushing above the pinion gear.----Don't forget the shift rod o-ring as it is a major source of leakage
 
I bought a 1975 6Hp Johnson outboard for my 14 ft aluminum v hull to get around small lakes. Paid 200 dollars and it runs great. I went through it cleaned it up, changed spark plugs and it ran on the first pull in a barrel. Went to change the gear oil and it had some water in it and wasn’t draining well and was pretty low. I pumped some new Johnson gear oil to get it to run out and let it sit for a day. Went to my local marina and purchased new gaskets for it and filled the gear oil. Ran it on the water twice and it ran great no issues. Went to drain the gear oil to see the condition of it and it was milky again. What should I replace next?
Your prop is the color of milk.what color was the oil you put in?
 
Definitely follow Racer and Boobie's advice. Another possibility is the milky oil the 2nd time was caused by residual moisture in the lower unit that mixed with your new oil. Regardless, the fact that you had that much moisture in there the first time says that a seal is probably bad somewhere. Find it, fix it, and then refill the LU. Run it for a short bit and then drain and refill again to make sure all the water has been removed.
 
Agree to all, I’m going to try to Pressure and vacuum test it. But not sure I have the full capability to do it. I could surprise myself. Does the motor have a seal kit available to buy on this website? I tried looking but was unable to identify the correct seals and o ring racerone was referring to.
 
It gets frustrating.----I asked for the model # and indeed your model # is a 1975.-----But there are 3 different seal kits listed ( after market SIERRA ) depending on what lower unit you have or is installed on yours.----18-2679 , 18-2680 ,18-2681 ----If the lower unit was in my hands it would be easy !----Shift rod o-ring is 0301877 all day long.----That shift rod o-ring can be replaced without pulling the bushing too.-----But I also have the factory tool ( more than 1 ) to remove the bushing.
 
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It gets frustrating.----I asked for the model # and indeed your model # is a 1975.-----But there are 3 different seal kits listed ( after market SIERRA ) depending on what lower unit you have installed on yours.----18-2679 , 18-2680 ,18-2681 ----If the lower unit was in my hands it would be easy !----Shift rod o-ring is 0301877 all day long.
Thank you so much! I’ll look into which lower end unit!
 
Is the gearcase the exact same color as the rest of your motor , yes or no.---Any evidence that it has been repainted ?
 
That is not a 1975 model going by the cosmetics / cowling / paint colour !!-----Another reason why I asked for the model # going by the paint colour in post #1.-----But most folks would not believe that anyway.----I say it be a 1968 and maybe check the disc on the block to see what # is on it !!
 
That is not a 1975 model going by the cosmetics / cowling / paint colour !!-----Another reason why I asked for the model # going by the paint colour in post #1.-----But most folks would not believe that anyway.----I say it be a 1968 and maybe check the disc on the block to see what # is on it !!
Oh wow! There was no ident plate, and I looked a P/N off the the head and found it to match a 1975. That is my bad. I guess you could say you know these motors pretty well. The shiny circle disc reads J2911501.
 
Do I know these motors ?----Take it apart every nut and bolt, throw in some extra parts or leave some out.----I put it together without having to look into a manual or order a single part for it.----I have many of these wonderful 6 HP motors on hand & parts galore.
 
Do I know these motors ?----Take it apart every nut and bolt, throw in some extra parts or leave some out.----I put it together without having to look into a manual or order a single part for it.----I have many of these wonderful 6 HP motors on hand & parts galore.
That’s awesome. It runs great after I changed the spark plugs and changed the fuel line. Starts on first pull everytime. How you can identify the motor year from the J number?
 
This motor was NEW when I started working at a JOHNSON dealer in 1968.-----I can identify it in 1 1/2 seconds by looks from 20 feet away.
 
This motor was NEW when I started working at a JOHNSON dealer in 1968.-----I can identify it in 1 1/2 seconds by looks from 20 feet away.
Racerone, quick question. How could water be getting in through the shift rod o ring when it is never under water?

nevermind I'm an idiot, I looked at the wrong drawing PN is still #0301877.
 
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