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Mercruiser 3.0 Alpha outdrive leaking oil out of water inlet???

gkm24

Regular Contributor
I have just bought a boat with a Mercruiser 3.0 and an Alpha outdrive.The boat is 18 foot with a small front cabin and is in good condition.
I bought it cheap from a friend of mine who lives on a freshwater lake and has a mooring. He came out one morning and the boat had settled on the bottom. Not totally submerged but enough to get water in the engine.
I have pumped all the water out, drained the engine, put the boat on the trailer and put lots of oil in the engine and bores etc. I will start it as soon as possible.
We can't find out how the water got in but there is what smells like gear oil leaking out the drive leg water inlet (where the muffs fit to flush the engine).
there is still oil in the top up bottle for the outdrive but it is low. Could this be a key to how the water got in?
Both bellows and water pipe on the drive are new and in good shape with no cuts from what I can see at the moment.
Thanks for any help.
 
1. if water got high enough in the boat, remove the outdrive and get all the water out of the large bellows, it will be full............

2. water can not get into the boat from the gear oil system at least not enough to cause the boat to sink.

3. if enough water got into the boat to sink it, it is either the u joint bellows has a tear in it or loose (large one) or shift cable bellows is torn or loose.
In rare cases it may be the transom seal but very rare!! If none of these then waves or rain...........

4.if water got high enough to get into engine it most likely got in thru the dip stick.....

5. if gear oil is leaking from outdrive you need to remove the drive, drain the gear oil and pressure check it and determine if there is a leak.
if the bottle is low and the gear oil is greenish blue as it should be then no water has made its way back up the hose or thru the cap.

Before you start your boat motor, pull all the plugs and leave them out, make sure you only have the correct amount of motor oil in motor, 4-5 qrts!!

turn motor over many times without the spark plugs and get any water out of the cylinders.......

Once you are sure of no water, reinstall spark plugs and put outdrive back on and hook up water and start motor.

If water got into the oil system it may take several oil and filter changes to get it all out.

If you cant determine how the water got in what can be done is to lift the trailer up from the front as high as you can get it (like 3-4 feet high) and fill the boat up with water from the inside and see where it leaks out from..........also make sure the transom plug is good and installed.
Just don't let the water get high enough inside the boat to get into the motor again.........

Also the starter life span may be lessened from water contamination.
 
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Thanks for the reply. The oil is greenish blue as you stated and is still leaking out of the leg. All the water is out of the motor now(plugs removed and water sucked out etc) and it has oil back in it. Just need to check the carb but not sure that the water got that high up.
Can I run the engine with the out drive removed?
I would like to start it up as soon as possible to get oil all round the motor.
I will check the bellows again but They were replaced by a marina a short while ago and look to be good although it still could be the fault. Luckily it was fresh water and not salt water!
 
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