1996 Mercury 60 hp Bigfoot leaking lower unit fluid

[HAHPontoon]

I have a 1996 Mercury 60 hp Big Foot with the following specs.

2 stroke
Model 60ELPTO
3 cyl

I had a starter solenoid go on out on Saturday. Pulled the boat out of the lake and back to the house. It sat overnight and I noticed that it has a slow leak of lower unit fluid. It has only leaked a few drops in the last 24 hours, but enough to be concerned. Its leaking out of the lower water intake hole, which seems like odd spot to leak lower unit fluid. Any ideas?

I'm pretty experienced with working on i/o's, but this boat is my first real adventure into outboards. Guess I'm going to become a boat mechanic one way or another!

I did find the online service manuals on here. Those should be a big help.

 

[HAHPontoon]

Re: 1996 Mercury 60 hp Bigfoot leaking lower unit fluid

From doing searches on here, I'm going to start by replacing the lower unit oil and drain/fill/vent seals and then running it again and see if its still leaking. Its not leaking bad, maybe a tablespoon in 48 hours, but enough to be concerned about.

 

[CV16]

Re: 1996 Mercury 60 hp Bigfoot leaking lower unit fluid

Are you sure it's not just oil from the premix gas?

 

[HAHPontoon]

Re: 1996 Mercury 60 hp Bigfoot leaking lower unit fluid

Are you sure it's not just oil from the premix gas?

No, the oil is honey colored and smells like gear oil. I use the Quicksilver injection oil and if it was leaking down, it would be a bluish color. That was my first thought that it was just residual injection/exhaust oil leaking down given the starting issues that I was having with the starter solenoid and screwing around with it.

 

[HAHPontoon]

Re: 1996 Mercury 60 hp Bigfoot leaking lower unit fluid

Wow, lots of responses so far . I'm going to change the fluid and see what happens.

 

[oldman570]

Re: 1996 Mercury 60 hp Bigfoot leaking lower unit fluid

If there is no or very little water in the LU when drained after setting for 24 hours it is not bad leak and most oil leaks will be at the prop shaft seal or the LU drain plug. Ring gaskest for the LU drain plug and fill plug should be replaced often as the are pressed and will leak. Most all oil Injection or other will be honey colored when mixed with water. If leak is at the water intake area the seals on the drive shaft waterpump could be leaking but doubtful If correct LU oil and not over filled. Sound like burned injection oil as stated by CV16 .
Oldman570

 

[HAHPontoon]

Re: 1996 Mercury 60 hp Bigfoot leaking lower unit fluid

I got new Mercury gear oil and drain plug seals from the dealer. Got home yesterday and drained the fluid. About a pint of water came out first. :facepalm:. Then milky, nasty oil. I flushed it with gear oil and let it drain overnight. Filled it with merc gear oil and took it to the lake. Put it in reverse to back it off the trailer and it started making a bunch of noise. . Left it on the trailer and brought it home. Off to the boat mechanic. This is going to be expensive.

 

[aussieflash]

Re: 1996 Mercury 60 hp Bigfoot leaking lower unit fluid

Id never have my prop spinning off a trailer at a boat ramp.Too many things could go wrong.Why not just push it off,then start it.
Seen ppl blow motors driving on to trailers also.
What noise you got?Engine or lower unit?Did you have leg off and mess up gears?Motor was in water or out?

 

[oldman570]

Re: 1996 Mercury 60 hp Bigfoot leaking lower unit fluid

I use diseal fuel to flush out LU's while still on the motor as it is easier go get and a gal. will do the job easy. You have to let the LU set for a while after fulshing to get all of it out and put the new LU gear oil in. When you got that much water out before the milk started should have been a bad sign. If it was only a table spoon or two would have been a indication that it need to be looked into. You can buy rebuit LU's and put them on yourself and probley save a few 100 if so inclined. Get a price from the local man and check online for prices for a rebuild with a garennty ,then make the decidsion. There should be some up by the Big Lakes near you.
Best of Boating Oldman570

 

[donaldboyer]

Re: 1996 Mercury 60 hp Bigfoot leaking lower unit fluid

Id never have my prop spinning off a trailer at a boat ramp.Too many things could go wrong.Why not just push it off,then start it.
Seen ppl blow motors driving on to trailers also.
What noise you got?Engine or lower unit?Did you have leg off and mess up gears?Motor was in water or out?

I drive my boat onto my trailer most times! Can you explain how motors blow because of this?

Not doubting you, just a little worried I may not be aware of a potential disaster!

 

[oldman570]

Re: 1996 Mercury 60 hp Bigfoot leaking lower unit fluid

Not all people back the trailor in the water far enough ,and power the boat onto the trailor. As the boat comes out of the water the backpressure on the prop and exhust is lessend and a chance of the motor over reving and blowing, if near or at WOT, could and has happend. Seen it happen twice last year at the marina. I even learned a few new words there when it happened. Its fine as long as the trailor is in enought and you don't have to power it on at WOT as some people do.
Oldman570

 

[HAHPontoon]

Re: 1996 Mercury 60 hp Bigfoot leaking lower unit fluid

Being on a pontoon, the trailer is long enough to get it on and off with the lower unit always staying submerged. The noise was coming from the lower unit. The engine started and ran fine. Just when I put it in reverse, the lower unit started making noise. I was going to have my wife back up the truck and tap the brakes to launch me off, but once I heard that noise, I didn't want to risk running the LU any more.

I didn't think of using diesel fuel, but with that much water, I'm thinking the damage was already done anyway.

Thanks for the suggestion Oldman. I may at least find out what a rebuild lower unit would costs. May be the cheapest route to do the job.