neglected mercruiser 2.5 - water in oil, dirty gas etc

[vroom ZOOM]

Hello.
this mercruiser 2.5 I got a week ago turns out to have water in the oil. is this a serious issue, or just an oil change? I dont think this is a surprise since the previous owner had the fuel line wrecked, the air filter off and the motor under direct rain in this form. havent checked the plugs to see if there was water in the cylinders. I fixed the fuel line, attached the battery to try fire up the engine, but no luck. I know it runs if you put gas into the carb, but it turned out that I cant even get the fuel from the tank to the pump. upon taking apart the pump I found it absolutely dry, and I cannot get the fuel from the tank. should I replace the fuel line or is there a screen or floating pickup which is so stuffed up with crud that I even cant blow through? I will get the brutal air compressor if I cant clear it, to clear it! (not through the pump of course!. also, what oil should I use in the engine? the cap says 10w 30, the motor says sae40. what should I use?

 

[Scott Danforth]

could be water from rain....could be water from cracked block

run it from a small 1 gallon tank until you get your tank squared away.

use rotella T4 15w-40 for oil

 

[vroom ZOOM]

Ok, thanks, I will change the oil and see how it goes.

 

[vroom ZOOM]

ok, changed the oil, ran the motor for a bit, and have a few issues. first of all, the oil level has gone down to near the bottom of the dipstick. the oil is milky. I havent changed the filter so could have the old oil and the water left from the old oil and in the oil filter cause this? also, is the oil level going down a problem, or normal once the oil pump takes in some? next problem is that I have water dripping around the starter/flywheel/gimbal area. I am not sure if it is coming from the drive or motor, will pull the drive to see if there is anything wrong with the water pump area. third, the water doesnt seem to be reaching the motor. this seems to be related to the second problem? also, how could the water get into the oil if its not reaching the block? or is it reaching and draining into the oil pan? If that was the case the oil level would go up, not down? I took out the drain in the block but all that was there was a few drops of water and a couple of little caterpillars. the block appears to be fine from the outside, but could it be horrible inside? I checked the plugs and they seem to be fine, no moisture, dry, evenly firing and no rust. fuel pump seems to be working well now. also what is probably a carb issue, the motor seems to have a lot of "up and down" when idling. when warming up the motor runs well and smooth. is all of this normal for a motor that has sat for years? I need help with this merc to get it up to par again. thanks for the help.

 

[thumpar]

The filter is part of an oil change. Without water in the block there is no way to tell if you have water coming in from a crack or blown gasket other than to do leakdown/compression testing. Most likely you have a bad impeller but could be a clog or the impeller is not turning at all. You have more work to do.

 

[vroom ZOOM]

ok will replace filter. there is water coming in near the bilge when I start it up with ears so it just must be a clog. will pull the drive and see

 

[thumpar]

Water should not be coming in the bilge. Find out where that water is coming from.

 

[vroom ZOOM]

ok , got the no water to engine problem solved, getting good water flow now. turned out that the water supply hose was disconnected by some idiot. when I took out the engine drain plug there was a considerable amount of slightly rusty water. however, when I took out the manifold drain plug it was dry - no water at all. only a few grains of sand.

 

[achris]

OK, having run the engine for a while with no water, you need to check (with the view to replacing) the exhaust shutter and the water pocket cover (in the drive).... Both of those items are in the exhaust path and don't fair well with red hot exhaust gases...

Chris...........

 

[vroom ZOOM]

the motor only ran for a few seconds, so it didnt even warm up, but where is the exhaust shutter located? also forgot to mention that there is still water coming out around the exhaust area.

 

[achris]

... where is the exhaust shutter located? ....

As you haven't provided an engine serial number, or even a year of manufacture, the location of the shutter can only be described as 'somewhere between the exhaust elbow and the gimbal housing'.

And if you do tell us the year, make sure it's of the engine, not the boat (they are not always the same )....

Chris.............

 

[vroom ZOOM]

ok, engine is a 1987 GM 153 ill have a serial number soon

 

[vroom ZOOM]

will pull the motor out of the boat to have a goooooood look at the flywheel area to pinpoint the cause of the water running out of the starter area. I know there are some frost plugs and oil plugs in the back there so I think they may have popped. will do a pressure test later on

 

[achris]

Once you have the engine out, you can look down the exhaust pipe and see if the shutter is still there.

Chris..............

 

[vroom ZOOM]

ok, pulled the motor and flywheel and the frost plug in the back popped out. water in the oil - 90% chance the block is (cant swear on forums) other 10 % is that the water got in via rain and the frost plug saved the motor? what are my options now? I have a feeling that a 120 is a bit too small on a 19 foot maxum.

 

[vroom ZOOM]

also, will a 4.3 just drop in or not?

 

[Bondo]

Ayuh,...... I'd think there's a 100% chance yer workin' on a freeze busted junk anchor motor,......

To swap in a 4.3l, ya need pretty much everything from the pulleys to the prop,.....
And some glass work to build new motor mounts,......

 

[vroom ZOOM]

well, what are my best motor options then? I dont mind a bit of glass work, I am just concerned if everything will work out with the original gimbal area

 

[vroom ZOOM]

is 250 an good price for a good running 1993 4.3 ?

 

[Bondo]

Ayuh,..... At that price, it's incomplete or don't run,...... aka: a parts motor at best,.....

'n yer drive gear ratio is very wrong,.....