• GUESTS

    If You  want access  to member only forums on FM, You will need to Sign-in or  Sign-Up now .

    This box will disappear once you are signed in as a member.

  • WE CREATE LONG TERM, MEANINGFUL RELATIONSHIPS IN HERE ... PLEASE JOIN US.

    You know what we all love...

    RECEIVE THE GIFTS MEMBERS SHARE WITH YOU HERE...THEN...CREATE SOMETHING TO ENCHANT OTHERS THAT YOU WANT TO SHARE
    When you enchant people, you fill them with delight and yourself in return. Have Fun!!!

  • 0
Sign in to follow this  
countryboy9799

Lower unit oil turning black on evinrude

Question

countryboy9799

Hi all,

I have a 1982 70HP evinrude and for the last two times I have changed it the lower unit oil had been black, didnt look like there was any water in it. I dont remember it turning black when I have changed it before and was wondering what your thoughts where. Thanks

Share this post


Link to post
Share on other sites

8 answers to this question

Recommended Posts

  • 0
theoilman

Short of having an oil analysis done you will never get a completely accurate answer. You're right, normally black will not be water. Usually water, even as little as a few percent water, will turn frothy/milky. Have you changed brands of oil? Have you changed the specification of the oil you use? I have seen some automotive gear lubes that do not carry the marine specs turn black when used in an outboard lower unit, and I have no idea why. (I have not bothered with the expense of oil analysis to find out. Oil analysis will cost typically around $25.) I have never seen a marine spec. gear lube turn black.

Share this post


Link to post
Share on other sites
  • 0
shamrock7

Does the Lower unit grease smell burnt? If so, you probably have a bearing or gear issue that is causing excessive heat which is breaking down your grease.

Share this post


Link to post
Share on other sites
  • 0
Surface Tension

Gear oil has a pungent smell to begin with so the smell test can be deceiving. To turn black isn't normal. My first thought is heat. That could build up in two places. The lower unit, which could be the case but being in the water with good contact to the housing, seems unlikely. Another guess and might be more likely is the drive shaft bearing just below the water pump. This is in a spot of the drive that is under water but not in direct contact with water.

If you were low on oil or your bearing was wore it can create heat. If either were the case your looking at complete failure soon. Next thing to suspect is a bad impeller. Might be enough to cool the engine just enough to the point where it won't seize from over heating but to the point where the exhaust is very hot. That water that should be exiting out your through hub exhaust isn't there and your lower drive will get very hot. High heat exhaust with no water is coming out that through hub exhaust and could very well be scorching your gear oil.

About using Automotive Gear Oil instead of Marine Lower unit Gear Oil. The RPMs on a lower unit are extremely high, much higher then an automobile. The formulation between the two are different. Automotive gear oil in that high RPM situation will be whipped into a froth. It will have no choice but to expand. What happens next is your water tight sealed system gets blown from the pressure build up. There goes your seals. Gear oils leaks out and water moves in.

Share this post


Link to post
Share on other sites
  • 0
countryboy9799

I have been using pennzoil gear lube that is marine grade, bought at walmart if that helps. I do have a good stream of water coming out the hole on top if that helps also, I could change the impeller as its been awhile. The last time I changed the impeller was a few years ago and that was when my problem started.

The motor was ran for about 30 seconds out of water and ruined the impeller. How would that be connected to the problem I am having now? I know the prop turns easily so I doubt the bearings in the lower unit are bad but maybe as SF said it could possibily be the upper shaft bearing. I have been going two years on the oil change and I wonder if a bearing would hang in there that long, I wouldnt think so.

I have felt the lower unit temp by hand after it has been ran awhile and it has always been similar to the water temp, definatly not much warmer anyways. I would like to get this fixed before anything major breaks thats for sure. Is there any way that the exhaust can get into the oil where it may be getting sooty?

Thanks for the help guys.

Share this post


Link to post
Share on other sites
  • 0
Surface Tension

If exhaust was getting in then water would be getting in too.

The lower unit is made from aluminum. It could be that aluminum is going though oxidization and turning the gear oil black. 2 years on an oil change, this could start to show up I guess.

If the lower unit gear oil level has been been full, doesn't smell burnt, and you can't see any metal specs in the drain oil, you haven't been overheating, then you might just want to replace the oil and check it often.

As you found out running the outboard without cooling will ruin the impeller fast. Doesn't take long so I wouldn't do it even for a few seconds. Could something in the lower unit been damaged during that short run. If it did the hot exhaust going though the and around the lower unit would be the culprit.

Share this post


Link to post
Share on other sites
  • 0
countryboy9799

What does this mean if the aluminum is oxidizating? Maybe when I ran it without water it cooked the oil and it just needs to be cleaned up with some oil changes?

As far as metal filings I only found a few flakes of metal on the magnet which is normal. I will change the impeller before spring and do a mid season change next year, thanks for your help.

Scott

Share this post


Link to post
Share on other sites
  • 0
Surface Tension

Even run you hand along bare aluminum and it turned black?

Share this post


Link to post
Share on other sites
  • 0
countryboy9799

I haven't done this, really havent worked with aluminum much. What would this mean to me? Any future problems?

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  

Announcements



  • Your Responses - Share & Have Fun :)

    • skyking
      Was up last week on Kab and it seemed that your bait depended on where you were fishing. Some areas leeches did good, but others minnows were the go to. We lindy rigged the entire trip and on days when wind was gusty we did pretty good shallower with minnows in 13 to 20 ft....then some areas we were doing better with leeches 16 to 32 ft. No wind was like the dead sea.
    • Mike89
      catch and eat the crawfish too!!!
    • Uncle Boney
      I can second A Warrior.  Jumbo leeches for Walleye.  Northern were more interested in minnows and crawlers.
    • Harry Goodliffe
      A Carp Anglers Group Fishing social will be on June 23rd in Coon Rapids. If you enter the park from the Coon Rapids side (Egret Blvd), take a left from the parking lot and drive towards the picnic shelters. Take a right at the first stop sign and park in the lot. We will be fishing in the stretch or river behind the picnic shelter/playground. Start time can be before 7am and you can fish into the evening if you want. There will be medals for the 3 largest fish captured.
    • Gone Out Fishin
      Thanks for lots of good info guys.  Sounds like if I do things right I can have fish for breakfast, lunch, and dinner. I'll try fishing that reef for some evening walleye. Bobber fish for some sunnies in the weeds.  @delcecchi, I catch enough Walleye in the summer that I really don't want to ask. I won't shy away from a bite. I'll check that little bay for crappies.  @vermilionfox, Wow that is a lot of location data. My PROP thanks you for the rock info!  Merry Go Round? I have another question regarding the Rusty Crawfish... are they a problem on the west side of the lake too? Bloody mini lobsters. I remember spending lots of time using orange for bass and walleye since they were a major food source. Been years since I've done that.  Gone Out Fishin
    • Parmer
      I don't think you will be able to run it on that generator. I have a yamaha 2000 and I have not tried it yet but from everything I have read you need 2800 watts to start the AC. All the 2018 ice castle fish houses are coleman mach 3 plus AC I think. 
    • BigVwalters
      The fishing was pretty decent over the weekend.  Walleyes were biting on rigs with leeches or crawlers. Caught 12 between Friday and Saturday with with 4 nice slotters.   Biggest being a 24".   
    • Borch
      Star Island in Cass Lake has remote, boat in primitive camping as well.
    • A Warrior
      Just returned from a successful trip on Kab.  Minnows did catch fish, but leeches were the ticket
    • Rick
      Angling regulations on Lake of the Woods and the Rainy River in northern Minnesota would change under a proposal being considered by the Minnesota Department of Natural Resources to reduce the number of walleye and sauger allowed to be kept in the winter on the lake, and on the river allowing only catch-and-release fishing for those fish in the spring.  “We recently went through a public process of updating the Lake of the Woods Fisheries Management Plan and identified several potential areas of concern with regard to current levels of harvest,” said Phil Talmage, Baudette fisheries supervisor. “That’s why we’re discussing these potential changes.” The proposed changes would reduce the aggregate limit of walleye and sauger in the winter to align with the summer regulations on Lake of the Woods, and make spring angling on the Rainy River catch-and-release for walleye and sauger. The changes would go into effect starting March 1, 2019. Anglers will see yellow signs at public water accesses around Lake of the Woods and the Rainy River later this month notifying the public of the proposal. Future news releases will provide the details of a formal public comment period during the fall, and will include ways to provide comment to the DNR on the proposal. For more information on Lake of the Woods management go to mndnr.gov/lakeofthewoods. Discuss below - to view set the hook here.