1973 Merc 850, Urgent Help Needed

[scottrbishop]

Hey guys, I have posted here a few times now and gotten excellent help from this board, my thanks. I recently took the advice of this forum and SeaFoamed the carb and the cylinders in my 1973 Merc 850, and while I was trolling around at a local lake running it through the system I ran into a shallow spot and hit some rocks at low rpm's which ate up my prop significantly. I got a new prop, but now I am noticing when I take the boat out of the water, there is a steady drip coming from where the lower unit meets the motor, and it smells/tastes like a mix of gas/seafoam/lake water. I am thinking I may have hit those rocks and ruined the gasket that attached the lower unit, is dripping fluid a sign of that? The leak stops dripping after about an hour of sitting in my driveway, and I also noticed water coming out of the exhaust ports today when I had her our for a while running through some more SeaFoam (I don't know if that's normal). I have a cabin trip (only one of the summer) lined up for next weekend, and I need to know if what I'm seeing means that water is mixing with my oil, which I understand can ruin an engine. I am new to boat motors in general and would appreciate the two cents of anyone who has experienced this before. Am I good for the weekend, or should I seek out a marina before this weekend to check it out? I live in Minneapolis, MN, if anyone on this board would be willing to help, I would pay enormously to have the boat good to go by this weekend as most places around here give a two week advance on any motor work. Thanks in advance for any advice,

-Scott

 

[tashasdaddy]

Re: 1973 Merc 850, Urgent Help Needed

check the lower unit oil for water. open the bottom drain plug if it has water in it you will know pretty quick. if not go boating. but keep an eye on it.

 

[Clams Canino]

Re: 1973 Merc 850, Urgent Help Needed

There is no gasket where the lower unit meets the leg. Water out the exhausts in normal. Water also regularly drains after using these things. You're now looking for "trouble" and therefore finding it.

Further - lower units are a dime a dozen on ebay.

-W

 

[scottrbishop]

Re: 1973 Merc 850, Urgent Help Needed

Thanks guys! That restores some confidence in me for the weekend. Dumb question, but how do I check the oil for water? Again, thanks for the quick responses as now I can sleep at night .

-Scott

 

[USAFitz]

Re: 1973 Merc 850, Urgent Help Needed

it's pretty easy to check the oil for water. you have two plugs on the lower unit. Top one is vent and the lower one is the drain. (they are basically short screws). Unscrew the drain first, then the vent. Make sure you have a pan under your engine so the oil doesn't get all over the ground. Then let her drain. New oil is like the oil that goes into your car, but is colored for boat engines. Probably blue or green. When the oil comes out, if it's milky or if you can even see water in it, then you know.

p.s. you will need a small pump to put new oil back in. It attaches to the oil bottle and to the drain plug hole. Just pump it in till it starts to come out of the vent hole. Then replace the vent plug and finally the drain plug. Good luck.

 

[scottrbishop]

Re: 1973 Merc 850, Urgent Help Needed

Thank you sir, I'll try that when I get home tonight. Final questions, what sort of oil should I buy, and if I go my local marina and ask for an oil pump, will they know what I'm talking about? The help is much appreciated!

-Scott

 

[Plainsman]

Re: 1973 Merc 850, Urgent Help Needed

You can just ask for lower unit oil. They should know what the hand pump is.