Lower unit leak

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Charlie_merrifi

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So my 15 evinrude has been sitting about a month and i noticed a small puddle of what looked to be oil. Some in bottom side of prop and screw benieth it. How hard would this be to fix.
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Diehard

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just an idea but if thats a two stroke motor i think the exhaust comes out down there and some of the older two strokes have an extremely drippy oily exhaust pipe byproduct of the mixed fuel maybe not though. good luck
 
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Thuggin4Life

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You need to drain the lower unit oil. its like 7 bucks for a new tube of oil. you can see the drain plug in the first picture. its the flat headed bolt. there sould be another one above it somewhere. take the top one out. then the bottom one. catch the oil. if its creamy looking then there is water in the oil so there is a leak. but also it coould be mosture from it not being changed regulary. then with both bolts out you fill from the bottom hole until oil comes out the top. then you put the top one in and then remove the oil tube from the bottom and quickly put the bolt back in. then run the motor a few times out on the water or just let it sit in a barrel all day and run it for an hour or so and drain it again . if its not creamy then it was just old oil but if its creamy then there is a leak and ou need to replace all the lower unit seals. i did mine my self for around 75 but i had to replace a part or 2 that i broke and get a bolt machined out. so for about 50 you can get all the seals and do it youself. very easy for the backyard mechanic to do. lots of 2 stokes exhaust in the water through the prop and the air. the sludge in the pics kinda looks like exhaust sludge. 2 stroke motors do that sometimes. also trolling a lot builds that stuff up and when you run wide open it burns it out. i think the call it carbon build up or something. seriously change the lower unit oil though i bet i hasn't been done in a while. something that should be done at least once a year or every 100 hours or so of motor use. sooner when ran in salt.
 
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Charlie_merrifi

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Ok thanks. You fill from tge bottom hole. Wont it just run out that hole
 
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Charlie_merrifi

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How do you tell by looking at it where the exhaust ise
 
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mudslinging79

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yes, fill from bottom hole, otherwise you may develope a bubble if filing from top and womt get enough oil in the unit. the oil tube has a nipple like the caulking tubes have. snip the tip and stick it in the hole. you should be ablw to get a good seal to pump in the oil till it comes out the top. be sure to have the bottom plug handy for as soon as you remove the oil tube it will start running out the bottom hole.
 
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mudslinging79

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as for where the exhaust comes out, look at the center of your prop. it looks as if the middle may be a hollow tube, from your pics. my prop, for example, sits on a solid shaft with an acorn type nut on it, and the exhaust comes out further up the housing. one way to tell is fire it up with muffs, and see where the smoke comes from
 
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Charlie_merrifi

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Ok thanks. Where the water comes out is black is that normal
 
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Thuggin4Life

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Sounds like you need to take apart the lower unit. I bet several seals are bad.
 
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Charlie_merrifi

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How difficult is it to take apart
 
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Thuggin4Life

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very simple. first drain out the oil in the lower unit. then take the prop off. then there should be a fin on the motor above the prop. also this is where the lower unit mounts to the motor. should be 2 or 3 bolts. also you want the motor in nuetral. once the bolts are removed you just pull the lower unit down. now you should have the lower unit in you hand with the driveline and some of the water tube. should be a housing around the driveshaft on the top of your lower unit. this is were your water pump impeller is. as you take things apart you will see a bunch of seals and such. just remember to set things aside like the came apart. get the lower unit seal kit and a new water pump while you are at if any of the seals look bad or if there is water in the oil you drained out of the lower unit. then just put it all back together with your new seals and bolt it back on. if your seals are shot you will be getting water in the oil. if the are really bad you could posibly be getting oil in the water pump thus making the water dirty giving you the black on the peehole. might as well blow out the water intake while you have it apart. very simple to do and as you take it apart you will see how simple these 2 stroke boat motors that seem so complex at first really arent. also while you have it apart try to clean it up real nice. fisrt you really should just drain the oil and let us know how it looks. also when refilling oil when you put the top bolt back in befroe the bottom it helps make a vacuum so you dont loose much oil as you remove the tube and try to get that bolt in really quick. too bad you live so far away i wouldn't mind helping you tinker on the motor.
 
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Charlie_merrifi

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Maybe we can come up with something
 
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mudslinging79

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dont forget to undo the shift rods, there should be a lil plate on the side of the housing between the powqerhead and the prop. behond the plate is a coupler that holds the rods together.
 
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Charlie_merrifi

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Ok thanks. I did check and the leak appears to be coming out of the exhaust
 
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Charlie_merrifi

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So i finally got tge oil changed. Very black and smelled horrible. I noticed the leak again seems to be coming from where the prop meets the lower unit. It only drained about a silver dollar size puddle
 
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Thuggin4Life

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So i finally got tge oil changed. Very black and smelled horrible. I noticed the leak again seems to be coming from where the prop meets the lower unit. It only drained about a silver dollar size puddle
good news is that you aren't getting water in the oil so itas a better leak than some.
Are yoou saying that's how much oil leaked or how much came out of the unit? There should be quite a bit of oil in there as you know you just changed it. Also after changing it did the leaking oil look like brand new oil or old oil? kinda wondering how oil is getting out but water not it. could still be nasty exhaust maybe.
 
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Charlie_merrifi

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Thats how much leaked and was old oil.
 
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Thuggin4Life

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Well keep watching the leak. should change to new oil if its the lower unit leaking. sometimes outboards will have some nasty sludge in the exhaust.
 

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