No water circulation

Triam

Cadet
Joined
Sep 21, 2014
Messages
12
K, so I'm working on a stern-drive boat made by a company called BlueWater. It's a 69 and has a Mercruiser 120 engine. It's been sitting for almost 20 years. Yesterday I changed the oil and rigged the fuel system with a temporary tank. It started but we soon realized that there wasn't any water flowing through the engine. We had muffs hooked up to the outdrive but there was no water coming out with the exhaust. We took off the largest hose that goes to the water pump and it was dry and full of rust.

The question is: What should I do?
Should I just clean out the system hoping to find blockage that is causing this or should I replace the water-pump on the front of the engine, or something else? I've heard that in some outdrives there's an impeller that works in tandem with the water pump. Do I need to tear into the outdrive and replace that impeller?
 

alldodge

Moderator
Staff member
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Mar 8, 2009
Messages
40,583
K, so I'm working on a stern-drive boat made by a company called BlueWater. It's a 69 and has a Mercruiser 120 engine. It's been sitting for almost 20 years. Yesterday I changed the oil and rigged the fuel system with a temporary tank. It started but we soon realized that there wasn't any water flowing through the engine. We had muffs hooked up to the outdrive but there was no water coming out with the exhaust. We took off the largest hose that goes to the water pump and it was dry and full of rust.

The question is: What should I do?
Should I just clean out the system hoping to find blockage that is causing this or should I replace the water-pump on the front of the engine, or something else? I've heard that in some outdrives there's an impeller that works in tandem with the water pump. Do I need to tear into the outdrive and replace that impeller?

:welcome: to iboats

Dang sitting for 20 years, go figure. My guess is you have an Alpha drive which means your raw water pump is in the outdrive. Need to separate the drive and have a look, then replace the pump and probably the housing. With an engine sitting that long there could be all kinds of issues with the engine.
 

thumpar

Admiral
Joined
Jun 21, 2007
Messages
6,138
Most likely not a blockage but an old impeller. Split the drive and replace the complete pump including housing and base. Being a 69 it would be before the Alpha was around. Do you have a serial number off the engine and drive?
 
Joined
Mar 27, 2010
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3,008
Pull the drive off and run the engine off a hose. Stick the hose in the water inlet in the Bellhousing and let her rip, just make sure it doesn't fall out. The water inlet inlet is shown below in Fishermark's photo..

The left side opening covered in grease.

To be safe... you will need to do a boat load of engine and drive maintenance before it sees water.





Fishermark Water inlet.jpg
 

scatgo

Petty Officer 1st Class
Joined
Jul 13, 2014
Messages
362
The boat I have was sitting for only five years and I am having all sorts of problems including overheating because of it. After 20 years I would think the rubber impeller in the out drive has a bad case of dry rot but taking the drive off and hooking up a garden hose as mentioned will bypass the out drive pump and tell you if the water passages in the engine or exhaust manifold are clogged up with rust. Keep us posted.
 

scatgo

Petty Officer 1st Class
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Jul 13, 2014
Messages
362
This video will give you a idea of how much water you should get out the exhaust when hooked up to a hose.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Sitting for 20 years.... It's almost going to be easier and cheaper to pull the engine, drive and transom housings and replace them.... But, you have what you have. First thing, pull the drive as already said, and run the engine with the garden hose stuffed up the water inlet. See if you have something worth saving. If the engine runs ok, do a compression and leak-down test once it's warm. Once they check out, and it's then considered worth the effort. Without a question of doubt, the exhaust elbow will be up for replacing too. And pressure test the engine block, head and manifold as an assembly. No point in going any further if one of them is cracked. Split the drive and do a pressure test on the water pocket cover. If the gaskets in the bottom of the top housing is good, then you are good to go with further repairs. If the gasket fails, try and get it apart and replace it. If you start breaking bolts off, consider a SEI replacement drive (ratio is, or should be, 1.98:1). If the water pocket cover gasket if good, replace all the water pump components, housing, and base. Once all that is done, turn your attention to the transom housings. After 20 year of not moving, replace uni bellows, gimbal bearing, lower shift cable and its bellows, and the water supply hose. Be careful, as a 1969 model it will have the old bellows in, without the ridge.

Plenty of work before you even think about getting it in the water. I would consider working on that for at least a few months before it sees any water fun.... But the first thing I would consider, even before running the engine is parts availability. At 45 years old, a lot of the parts for that engine and transom assembly are NLA (No Longer Available), including important things like exhaust manifold and exhaust elbow. The drive is easy, any problems with that and just put a new SEI drive on... But engine and transom housings, not so easy. Yes, some here may say I'm being a pessimist, I say I'm being a realist.... ;)

Chris.......
 
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scatgo

Petty Officer 1st Class
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Jul 13, 2014
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362
@ AChris.......... SEI? Some of us newbies don't know what that stands for.
 

Triam

Cadet
Joined
Sep 21, 2014
Messages
12
The serial on the boat is 9B110 but I don't have a serial for the block or the drive. I'll get those next time I'm working on it. I've got it stored at a place I used to work at. They said they had space I could use which is nice, but what's not nice is that It's far from where I live so it's not often I get to work on it.
 

Triam

Cadet
Joined
Sep 21, 2014
Messages
12
Ok, so I've finally returned now that school is out. Stern drive serial is 2583151. Engine serial is 3915983 J298 VI22I6BC.
I took the hose off that goes from the outdrive to the water pump on the engine and hooked the garden hose up there and started the engine up. The amount that came out was pretty close to what's in the video above. We tried it again with the muffs to see if anything would come out where the hose goes from the outdrive to the pump and nothing did, so we're pretty sure we need the new fresh water impeller, but not a water pump for the engine.
We were going to take the outdrive off but I had seen an instructional video that said that the outdrive doesn't come off unless the transmission is in forwards. Is this true? My throttle cable is completely shot so I couldn't do that. On a related note, how do I know what type of cable I need?
Can anyone tell me what model exactly of outdrive I have here?
 

Triam

Cadet
Joined
Sep 21, 2014
Messages
12
One more thing.
20150525_184141.jpg
We need the lower drain plug. In the 20 years it's been lost. It's about .500" in diameter and we've tried 1/2-13 1/2-20 and 1/4 NPT and none of them go in. Does anyone know where to get a new plug for here? Could it possibly be M12? When we tested the water pump we had the dumbest guy present plugging the hole with his finger.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
Your not paying attention, you were supposed to remove the drive first, then put a hose in the water inlet. Doing it that way you destroyed whatever was left of the impeller .a 1/4 inch pipe plug is almost a 1/2 inch in dia.
First thing you need to do is locate manual 1 and do some serious reading before you do a FUBAR
shift cable has to be in full fwd, , the brass shoe must face bow to stern before the drive is removed .If necessary cut the shift cable at the transom and manually put it in full fwd.
 
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Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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47,309
Pull the drive, you have toased what ever was left of the raw water pump.. You will need to most likely reseal the entire drive as well. Your bellows are toast from sitting. Time to get familiar with MC drive maintenance.

The block drain is 1/4 NPT which is about 7/16" in diameter
 
Joined
Mar 27, 2010
Messages
3,008
You have to shift the shifter to forward gear so the drive is in forward. You don't have a transmission you have an outdrive.

If your shifter is stuck.and you can't shift between the gears then remove the shift cable off the engine that goes thru the transom to the outdrive and push on the end of the cable..... then go outside the boat and try to rotate the prop CCW while looking at the bow of the boat. If it locks CCW that will be forward.

If you can't push that lower shift cable then it's corroded inside. It will have to be replaced also.
Ziggy photo.jpg



You'll want to get under there and look in the front of the outdrive you should be able to see the shift shaft. This is outside the boat looking at the front end of the outdrive.... That needs to be straight to pull the drive off the boat, straight is Forward gear. If it's sideways like in the picture it's either in neutral or reverse.

You can tell by turning the propeller. If the shaft is not straight it could get bent trying to pull the drive off the boat.
 
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UncleWillie

Captain
Joined
Oct 18, 2011
Messages
3,995
You will know it is in FORWARD if you can Not turn the Prop CCW by hand,
But when turning it forcefully CW, you can feel the clutch jumping Splines... Click, Click!
 

NHGuy

Captain
Joined
May 21, 2009
Messages
3,631
So, to reiterate, and explain a little. The drive needs cooling water when it runs just as the engine does. If you water the engine and run the drive dry you chance wear on water cooled and lubricated bits in the drive.
So before running again.
Remove the drive, here's how.
Find a way to put it in forward. Since your throttle won't budge remove the lower shift cable at the shift plate and push in til it stops, then turn the propeller counter clockwise til it stops. Hold it there with a bungee to retain forward gear. This causes your shift shoe and foot to be aligned straight ahead so they can slip apart when removing the drive.
Next remove any trim rams or devices that will keep the drive from coming off. I forget how that drive tilts but whatever would keep it on the boat has to disconnect.
Remove the 6 retaining nuts that hold the drive onto the bellhousing. Attempt to remove the drive.
At this point the drive should come off. What could stop you are a few things. There is a gimbal bearing in the transom, through which the drive shaft passes. We have heard of driveshafts sticking there. And there is a splined coupler behind the engine which that same shaft contacts to pick up the engine power. I'd get some good penetrating oil onto the gimbal bearing. PB Blaster is the stuff, smells bad - works good!
If the drive won't slide back you can coax it with a 2x4 fulcrum behind the transom plate. It's OK if it pulls the bearing out with the driveshaft. You have to replace it any way.
Keep us looped in!
 
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Triam

Cadet
Joined
Sep 21, 2014
Messages
12
Thanks for the advice guys. It's too bad I toasted that impeller, but I'm glad it's not something bigger, and that it's something that would've needed replacing soon anyways. I won't get back to this project for at least another week, but I have a few questions to get me going in the meantime. Where do I get the spec to replace that throttle cable? Does any cable work or do I need to get measurements off mine? Do I need fittings to go with the cable I buy? Can anyone tell me what model outdrive this is specifically and can you tell me what kit to get to replace the water pump and where to get bellows?
I tried a 1/4NPT plug which I am positive was 1/4NPT (I'm a machinist) and it didn't go in. Perhaps the threads are buggered up and I need to run a tap down it. Anything else I need to do in preparation for my next try at this?
 
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