Hello all. I don't know a whole lot about boat motors so I thought you guys could probably help me out.

I bought a boat recently and am prepping it for the water. It originally had a short shaft, but was converted to a long shaft (before I bought it). I tested the motor in a large bucket of water and then drained the gear lube. When testing, I noticed some water leaking around the extension piece between the upper motor and lower prop unit. Is this area supposed to be sealed and if so, with what? The gear lube was also milky. Since water is mixing with the oil, how can this be fixed? I've done a little research and found that it could be any of these items: drain/fill and vents screws have bad seals, leaky prop shaft seal, or leaky lower unit seals. Anything else I could be missing? And how should I proceed? What should I replace/fix first? I read something about a pressure/vacuum test...is this something I should do or just have a repair shop do?

Little more history: the guy I bought the boat from told me of this problem but said that every time he used the boat, he would drain the gear lube when he was done fishing, and then put in new gear lube before he took the boat out again. He did this for 2 years with no problems. And me, with little boat motor experience, figured that I could eventually replace whatever seals were bad. Will this destroy the engine and can I continue to repeat this procedure?

Any help anyone can give will be greatly appreciated. TIA!

If it were mine, I wouldn't want the hassel of draining the lube each time.  If you fish very much, your oil would cost more than a fix in a short time.  I would take it to a repair shop and have the problem fixed right and be done with it.

If it were mine, I wouldn't want the hassel of draining the lube each time. If you fish very much, your oil would cost more than a fix in a short time. I would take it to a repair shop and have the problem fixed right and be done with it.

+1 on this.  By all means, get it fixed NOW.

You didn't say what kind of motor but when you said you added an extension and made it a long shaft, it sounds like on older Johnson/Evinrude.

If I guessed right, I don't think you're gonna wanna take it to a shop to be fixed because a reputable shop is not going to patch it and it's going to be way two expensive to have it properly repaired.  

Second, don't think buy a used one is going to fix your problem because those old LU's are subject to leak and a used one my start leaking or be leaking when you get it.

The good part is they are about the easiest LU made to work on so you could easily try repairing it yourself but the first thing you would need to check would be the drive shaft.  If the upper bearing in the LU hasn't damaged it, you are in good shape.  If it is damaged, you will need to see what a machine shop would charge to repair it versus what a replacement would cost.   If the drive shaft is in good shape, you can reseal it for less than $100 even buying the whole outer prop bushing unit, or less if you want to just replace the seals and orings in it.

I guess before going on, let me know if I'm guessing right and I can tell you what you need to do to reseal it.

Mercury 110 - 9.8hp Based upon the serial #s, a 1974-76. I didn't add the extension, I bought it that way. I'm not really sure if they guy I bought it off of knew what he was doing, or if he's not telling me what the real history is on the motor. I just want to get the boat on the water the cheapest way, but DO NOT want to damage the motor anymore than it appears to be.

Not sure if I explained this part right: the extension piece on the motor, is it supposed to be sealed on the outside with some type of marine sealant? To me, it would "look" pretty tacky, but I guess the part's underwater so who cares what it looks like.

Sorry, can't help you with the Merc's.  As for the leaking around the extension, I doubt that's a problem, I know it's not with the OMC's, in fact it's common.

As for getting on the water as cheap as you can, that usaully winds up being one of the more expensive ways to get there.  Most people find they could have bought a much nicer boat/motor for what they buy a "cheap one" for and spend the money needed to make it a good, reliable unit or find out it's just not worth spending the needed money on and have to junk it.

first off take it to a merc shop and have them look at it. If its a good shop they will fix it right. I would get all the seals changed on the lower unit, also get the impeller chaged while your at it. Changing the oil after each use is just a pain in the a@#!! Get it fixed right, it shouldn't cost that much.

as for the water coming out of the extenton. I don't think that is a problem, but tell the shop and they can let you know. that leaking water has no impack on your lower unit. take it and get it fix right, the first time, don't let a "buddy" fix it, take it to a merc dealer/shop and let them fix it the right way, that will be cheeper and better in the long run.