Drain Plug Locations: 1980 Mercruiser 330 MIE 454 GM V8

[1980Coronado]

I recently purchased a 1980 Century Coronado. This is my first Inboard. I've Winterized my 1968 Mercusier 140 I/O many times so I'm familiar with the process. However, this inboard stuff is new to me and I want to make sure I drain it properly. It's cooled with lake water, not a closed system.

It's easy to hook muffs up to an I/O to warm the engine...but I don't have a way to hook the inboard up to a hose. To compound things right now, I'm waiting for a new drive shaft to arrive and the old one is out of the boat.

It's getting cold and I need to at least get the water out of the engine. I haven't purchased a Seloc manual yet, because I'm not exactly sure which one I need for the Inboard.

Can anyone tell me how many drain plugs I'm looking for and where they are located? I can see both of the exaust drains. I'm assuming there are drains for the block on both sides. Are there others?.....I've read about water being used to warm the fuel. I've heard that the water pump may have a drain.

I'm going to dig into it this afternoon and go looking for drain plugs. I just want to make sure I find them all. Once I get the new shaft installed, I can put it in the water and run it to fog the engine and change the oil. I will obviously have to drain it again.

Once I drain it...can I just pour several gallons of antifreeze in the thermostat housing until it comes out the exhaust?

Thanks

 

[HT32BSX115]

Re: Drain Plug Locations: 1980 Mercruiser 330 MIE 454 GM V8

Howdy,

and welcome to iBoats!


Pictures? (we love pictures!)

I just looked at a picture of a 1980 Century Coronado. NICE!


You probably have an under-the-stern water pickup, that you could put water into to run it out of the water.

Another way would be to disconnect and extend the hose from that thru-hull pickup and put it into a bucket on the swim-step/deck/ or step stool etc, (as long as it's higher than the engine) so you could start a siphon into the raw water pump.

You just don't want to try to draw water up into the pump. It'll be running dry while you're trying to prime it.

There's also probably an oil cooler (and maybe a power steering cooler) that raw water runs through.

Drain them as well as the manifold/risers, block, and any hoses going to and from the raw water pump.

I haven't purchased a Seloc manual yet,

GOOD!

Just get a OEM manual from Mercury and maybe a manual for your Velvet Drive (if that's what you have) You might be able to find it on the internet....... http://www.kp44.org/ftp/VelvetDriveServiceManual.pdf


If the previous owner didn't recently change the raw water pump, you should probably change it.

If he told you he changed it, don't believe him and change it anyway!

They're a lot harder to change out in the middle of the lake with an overheated engine, a pair of pliers , Crescent Wrench and water spewing in all at once!!! !!!



Cheers,


Rick

 

[1980Coronado]

Re: Drain Plug Locations: 1980 Mercruiser 330 MIE 454 GM V8

Hey...thanks for the reply.

I started in to it yesterday afternoon and here is what I found.

2 drain plugs, one in each goose neck of the exhaust
2 drain plugs, one in each exhaust manifold
2 petcock valves, one on each side of the engine block.

Being unfamiliar with inboards, I just start following the water lines. The lake water pickup is on the port side of center, right next to the transmission through the bottom of the boat near where the drive shaft enters the hull. That hose runs to the starboard front side of the motor to the pump. The pump then outlets down the starboard side of the motor through a heat exchanger to cool the transmission fluid, a hose exits the transmission cooler turns down under the transmission and runs across to the port side, comes up and enters an engine oil cooler. A hose then exits the engine oil cooler going forward up to the engine water circulation pump.

I found a drain plug on the transmission cooler, but could not get a wrench on it. It looked like the transmission cooler was recently replaced. I could not get to the engine oil cooler easily at all. What I decided to do was disconnect the hose coming off the back of the transmission cooler and suck out the water with a wet-dry vacume. That hose is the lowest point since it runs underneath the transmission at the back of the engine block. There wasn't much water in there.

I do not believe there is a drain at either water pump. If there is I couldn't see one.

I never spoke with the previous owner. The boat was sold on consignment through Main Channel Marina on Lake Wawasee in Syracuse Indiana. http://www.mainchannel.com/On the test drive I noticed transmission slipage and a vibration at about 2500-3000rpm. The transmission was leaking but worked fine when filled. I had them completely rebuild it as a condition of sale. I also had them change the strut bearing, thinking that was the cause of the vibration. It was worn out and needed replacement. They had also put new impellers in it and done the routine service to prepare the boat for sale.

Anyway....the shaft was bent causing the vibration....I have a new one on the way. The water is out of the engine so I don't need to worry about freezing now. If we get some more warm weather, I may test the new shaft and then drain the water again. that will allow me to get some stabil in the fuel, change the oil, fog the engine etc.

One thing I had to do was drill and tap both exhaust manifolds for a 1/4" npt plug. The old 1/8" npt threads were gone. Someone put thread tape on the plugs to "fix it" the last time. Glad it held long enough for me to find it!

Ok now I need to ask a prop question...different thread...I know

 

[HT32BSX115]

Re: Drain Plug Locations: 1980 Mercruiser 330 MIE 454 GM V8

Great,


Sounds like you have it all covered. I'll bet the oil cooler was replaced due to freeze damage (most common)

Using the vac at the lowest point is a great idea.......BUT if you are at all unsure that you can get all the water out of any area, you might consider pouring some non-tox antifreeze into the system.....

It also was a good idea to drill and tap the holes for the next size plugs! (use brass plugs and a good pipe "dope" & they won't stick either)

Be absolutely sure that you use a thin screw driver, piece of wire, or other "poker" in the block and manifold drains to clear any rust flakes or other debris that could impede draining. (remove those block "petcock" valves so you can poke around in there)

Many an engine block has cracked because the "winterizer" didn't get all the water out of it!!

It appears that you got a pretty good deal!


Cheers,


Rick

 

[1980Coronado]

Re: Drain Plug Locations: 1980 Mercruiser 330 MIE 454 GM V8

I'm comfortable with it...there can't be enough water left anywhere to cause a problem. The petcock valves opened easily, and water flowed quickly through them. I've gone through this process with a 4 cylinder for many years...was just afraid of the "unkown" with the V8 and inboard...having not been around them at all. My first ride in one was when I drove this one!

I'm going to wait to put the "RV" antifreeze in it until I get the new shaft installed, just incase we decide to take it for a test before we put it in the barn.

You wanted pics...here you go

http://forums.iboats.com/album.php?albumid=598

 

[1980Coronado]

Re: Drain Plug Locations: 1980 Mercruiser 330 MIE 454 GM V8

Hey...BTW...you mentioned OEM Mercruiser manuals....do these still exist for a 1980 like this?......every search I do, I get a link to a Seloc book.

Never mind I found it....this is the one I need

#3 90-95693 1978-1984 Engines - All 4, L6 & V8


Looks like it's gonna be about $150.... Unless..I find someone with a PDF

 

[cr2k]

Re: Drain Plug Locations: 1980 Mercruiser 330 MIE 454 GM V8

Take the seawater hose off the back of the water pump, measure the nipple, go to NAPA and find a hose that has that size on one end and smaller on the other then you go to Home Depot get a female garden hose fitting and nipple that fits the smaller end and you have a flusher for your IB engine.

 

[HT32BSX115]

Re: Drain Plug Locations: 1980 Mercruiser 330 MIE 454 GM V8

That's a nice looking boat!

Someone here did have PDF manuals saved someplace I think........


You might post another thread asking for that specifically.



Cheers,


Rick

 

[1980Coronado]

Re: Drain Plug Locations: 1980 Mercruiser 330 MIE 454 GM V8

That's a nice looking boat!

Someone here did have PDF manuals saved someplace I think........


You might post another thread asking for that specifically.



Cheers,


Rick

Thank you....I grew up around a lake with a Century dealer and I always loved these boats as a kid......always wanted one. You just don't see many of them around. I don't think the made very many of them. They were just always a classy looking boat in my oppinion.

 

[1980Coronado]

Re: Drain Plug Locations: 1980 Mercruiser 330 MIE 454 GM V8

Take the seawater hose off the back of the water pump, measure the nipple, go to NAPA and find a hose that has that size on one end and smaller on the other then you go to Home Depot get a female garden hose fitting and nipple that fits the smaller end and you have a flusher for your IB engine.

I may just do that...sounds easy enough to rig up.