lower unit oil leaking - and not from the drain plug

[utah boat owner]

I just bought a 1971 Evinrude 18hp. Changed the lower unit oil, which had evidence of water in it. After filling with new oil, I took it out on the lake. I am now seeing an oil leak on the side opposite where the oil drain plugs sit. It is coming from some type of recessed hole, that maybe has a plug in it. Hopefully this is descriptive enough. The leaking "plug" is slightly above the center line of the prop shaft.

Can anyone tell me what the recessed the recessed plug is, and more importantly, how to fix the leak?

Thanks in advance.

 

[james__12345]

Re: lower unit oil leaking - and not from the drain plug

I have a 68 evinrude 18 hp. The only holes in my lower besides the oil drain and fill holes are on the same side as the oil fill and drain holes. They are holes to let the water that comes through with the exhaust to drain out. What color is the oil coming out of the hole you see, and how does it smell? If its dark and smells burnt, its most likely left over oil from the exhaust and the hole is just a water drain hole. If its white and has a sulfur smell to it, then that's low end oil, and I have no idea what that hole would be. Low end oil has a VERY distinct smell to it though. If you ever smell it once, you'll be able to tell it from two stroke oil instantly.

 

[geoffwga1]

Re: lower unit oil leaking - and not from the drain plug

The recessed plug you are referring to sounds like the pivot pin for the shifter fork.Is it a phillips screw? if so ,that's what it is.I expect the little "o"ring seal is damaged or missing and that is where your water is getting in and your oil getting out.The part # is 307853 (omc)or 18-7120 (Sierra).Be very careful not to move anything when taking the screw out to replace the o ring.Good luck.

 

[ilovevintage81]

Re: lower unit oil leaking - and not from the drain plug

Im having same problem but theres no screw there just hole and ive heard fatory drilled holes there but not forsure

 

[kfa4303]

Re: lower unit oil leaking - and not from the drain plug

HI Utah. The small blind hole on the opposite side from the DRAIN/VENT screws are factory drainage holes to allow any trapped water out of the leg. As long as the DRAIN/VENT/Phillips head screws are in their proper place you should be fine. However, if you are still getting water in the gearcase, you may have bad oil seals which need to be replaced. Not to worry, it's a simple DIY job. You can get a reseal kit right here at iboats for about $25. Here are some great links that will show you how to give your motor a tune up from top to bottom. Good luck. Holler if you get stuck.

Maintaining Johnson E & FD Serie
1971 Evinrude 18102S 18 hp Outboard Motor Parts
http://forums.iboats.com/johnson-evinrude-outboards/fastwin-lower-unit-seal-faq-277190.html

 

[james__12345]

Re: lower unit oil leaking - and not from the drain plug

The recessed plug you are referring to sounds like the pivot pin for the shifter fork.Is it a phillips screw? if so ,that's what it is.I expect the little "o"ring seal is damaged or missing and that is where your water is getting in and your oil getting out.The part # is 307853 (omc)or 18-7120 (Sierra).Be very careful not to move anything when taking the screw out to replace the o ring.Good luck.

The hole for the shifter fork screw is on the same side as the oil fill and drain holes and well below the prop shaft on my 68 18 hp, and from what I can tell from the diagrams here Evinrude Gearcase Parts for 1971 18hp 18103S Outboard Motor the 71 is the same way. I could be wrong, but it really doesn't sound to me like it would be the pivot for the shifter.

 

[geoffwga1]

Re: lower unit oil leaking - and not from the drain plug

OK,You are right,I was assuming you had the lu upside down in a jig,in which case it would have been above the level of the shaft,so the pivot pin is not your problem.The holes above the join are drain holes to stop water lodging there and freezing.I guess you have to think about a lu seal kit now,available from Iboats and lots of how to on here.