Lower unit oil

Ronniewhite

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May 26, 2022
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I changed the lower unit oil on my 2000 Johnson 25hp 3cylinder today because I'm tarping up my boat for the winter. The oil was like a yellow and really thick and creamy. It took like 15min to drain. It was minus 1 outside. Was the oil like that because of the cold temperature or was it because there's water getting in and it was half frozen. It had new oil in it in the may and I used the motor for fishing about once a week.
 

saltchuckmatt

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I changed the lower unit oil on my 2000 Johnson 25hp 3cylinder today because I'm tarping up my boat for the winter. The oil was like a yellow and really thick and creamy. It took like 15min to drain. It was minus 1 outside. Was the oil like that because of the cold temperature or was it because there's water getting in and it was half frozen. It had new oil in it in the may and I used the motor for fishing about once a week.
If you still have it see if it's separates. Probably needs pressure testing. Might want to wait until spring if you can't pull the lower and get it into a heated space.
 

Ronniewhite

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May 26, 2022
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If you still have it see if it's separates. Probably needs pressure testing. Might want to wait until spring if you can't pull the lower and get it into a heated space.
No I don't have it. It was like a Cadbury Easter egg. Those creamy ones they have at Easter time. That's what the oil was like
 

Crosbyman

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had the basic same issue on my 75 ETEC 2-3 years ago. I assumed the GC was the problem so I dropped the GC and took it home for the winter to do pressure and vacum tests .. in a warm basement :) all went perfect no leak ???

Ended up being a "reused crush seal" issue because I refilled the GC and stopped using " used " seals. never had issue come up after.

If you have no mono line tearing up the prop shaft seal I would refill & reseal with new crush seals and run a few trips with it. Recheck the oil for infiltration if... you don't have a pressure/vacum tester.

https://www.bing.com/videos/search?...D84144AD90360F195315D84&view=detail&FORM=VIRE
 

Ronniewhite

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May 26, 2022
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had the basic same issue on my 75 ETEC 2-3 years ago. I assumed the GC was the problem so I dropped the GC and took it home for the winter to do pressure and vacum tests .. in a warm basement :) all went perfect no leak ???

Ended up being a "reused crush seal" issue because I refilled the GC and stopped using " used " seals. never had issue come up after.

If you have no mono line tearing up the prop shaft seal I would refill & reseal with new crush seals and run a few trips with it. Recheck the oil for infiltration if... you don't have a pressure/vacum tester.

https://www.bing.com/videos/search?...D84144AD90360F195315D84&view=detail&FORM=VIRE
Actually I've probably changed the oil 4 or 5 times and I never changed those seals. They looked good so I thought they were good. They are those clear little rubber seals right? I will make sure I get some new ones before I run it in the spring.
 

Crosbyman

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round white washers (seals) that fit the bolt... not rubber... more like white nylon plastic...

very common outboard part

don't use hardware store stuff because the plastic material is much harder

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clemsonfor

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Sep 19, 2005
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I changed the lower unit oil on my 2000 Johnson 25hp 3cylinder today because I'm tarping up my boat for the winter. The oil was like a yellow and really thick and creamy. It took like 15min to drain. It was minus 1 outside. Was the oil like that because of the cold temperature or was it because there's water getting in and it was half frozen. It had new oil in it in the may and I used the motor for fishing about once a week.
Yellow as in honey or amber colored? That's what oil looks like when it's clean and new. Now if it was milky yellow and opaque it sounds like some water is getting in.
 

Ronniewhite

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Yellow as in honey or amber colored? That's what oil looks like when it's clean and new. Now if it was milky yellow and opaque it sounds like some water is getting in.
It was not the same colour as the new oil. It would be like the color of that creamed hunny that comes in a little plastic container.
 

Vic.S

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May 4, 2004
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I changed the lower unit oil on my 2000 Johnson 25hp 3cylinder today because I'm tarping up my boat for the winter. The oil was like a yellow and really thick and creamy. It took like 15min to drain. It was minus 1 outside. Was the oil like that because of the cold temperature or was it because there's water getting in and it was half frozen. It had new oil in it in the may and I used the motor for fishing about once a week.
The oil should remain "clear and bright" but perhaps just a little darker in color.
If it is turbid or milky looking it indicates water is getting in

It took a long while to drain because it was cold ......... warm it up a bit and it will drain faster. Warm the new oil before filling too and the task will be much easier.
 

Vic.S

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round white washers (seals) that fit the bolt... not rubber... more like white nylon plastic...

very common outboard part

Sometimes you will come across drain/ level screws with O ring seals but the screws for them are different.
If there is a recess on the underside of the head O rings are correct.
If the underside of the head is flat the flat plastic ( nylon??) washers are correct.
If you use O rings on the latter you will over-compress them
If you use flat washers on the former the head will stand proud and you may not get a good seal
 

Chris1956

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Mar 25, 2004
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Coated paper gearcase gaskets are the right ones for most applications. The nylon can be too hard to seal well. I never seriously tried the oring ones.

You need to dig the remains of the paper ones out of the gearcase when changing the oil, as multiple partial gaskets can leak. Amazon and other places have them in bulk.

Mercury Outboard gaskets also fit Johnson/Evinrude outboards and MerCruisers. Not sure about Yammies. as they require an adaptor to fill the gearcase with oil.
 

airshot

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It was not the same colour as the new oil. It would be like the color of that creamed hunny that comes in a little plastic container.
Depending on the mfgr of the oil and whether dino oil or synthetic will make the oil different colors. I use full synthetic which is like a very light honey color, but the straight duno 90 weight is much darjer almost like molassis or pancake syrup. I also have a blended gearboil that is a darker amber, so all depends !!!
 

dingbat

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Coated paper gearcase gaskets are the right ones for most applications. The nylon can be too hard to seal well. I never seriously tried the oring ones.
Not a fan of the old style slotted screw drain plugs or paper gaskets for the reason you noted above.

Switched to “new style” OEM Hex head screws with nylon gaskets and never looked back.

Could see getting the proper torque on a nylon washer being a problem using the slotted screw. No problem at all using an Allen wrench.

Evinrude OMC New OEM Fill/Drain Plug Screw, 0982851, 0912625, 0307551​

Johnson/Evinrude/OMC New OEM WASHER 0311598​

 

Crosbyman

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me.... I prefer slotted because hex heads are easy to strip... never went back to hex heads

Trying to remove s tripped he head is a real pia.
 

racerone

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Have to agree.----I like slotted heads.----Soft stainless hex heads are easy to damage / strip.
 

airshot

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The trick to the slotted screws is make a screw driver that fits.....as a retired tool maker, I saw the need for a proper fitting blade and one that is hollow ground. Also have a shank that is square to attach an open end wrench for leverage. Made my tool many years back, it doesnt bugger up the slot and will break loose the most stubborn screw.
 

Chris1956

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Gee, I use a hand impact driver. They come with various widths of slotted screw driver bits. If you use the impact driver correctly, the plugs do not strip.
 

Lou C

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Not a fan of the old style slotted screw drain plugs or paper gaskets for the reason you noted above.

Switched to “new style” OEM Hex head screws with nylon gaskets and never looked back.

Could see getting the proper torque on a nylon washer being a problem using the slotted screw. No problem at all using an Allen wrench.

Evinrude OMC New OEM Fill/Drain Plug Screw, 0982851, 0912625, 0307551​

Johnson/Evinrude/OMC New OEM WASHER 0311598​

I’ve been using those for years on my Cobra they are much easier to deal with than the old slot style. The hex head Allen style won’t strip as long as you use the right size….keep in mind there are US size Allen fittings and Metric…
Also ALWAYS replace those white fiber sealing gaskets! They get grooved when tightened & will often leak if reused.
 

Crosbyman

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I think BRP uses US size 5/32 Allen on OEM ...but I have managed to strip them. boils down to preferences I guess.
 
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