water backing up into engine from outdrive?? help

OllieC said:
Yup - replaced my cracked one last Spring. Had the notorious slow drip at the blue plug.
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one of mine had a crack at plug and the last "mechanic" epoxied the blue plug back in. changing the manifold is really not that hard, at least on the port motor. starboard might be a bit harder since there is an engine support stringer there. and that one has a drip. should be fun.
 
Nater Potater said:
Shoulder surgery? Get well soon! At least you picked the right time of year to be out of commission.
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Lol. I planned it like that. Winterizing at the last min want smart. But it's not freezing yet. Lol
 
StormSplurge said:
one of mine had a crack at plug and the last "mechanic" epoxied the blue plug back in. changing the manifold is really not that hard, at least on the port motor. starboard might be a bit harder since there is an engine support stringer there. and that one has a drip. should be fun.
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When mine split, I epoxied a small bolt with washers into the broken part of the manifold and ran the boat until the replacement was available. I have to say, the thought crossed my mind to leave the repaired one in place since it proved itself to be robust but I ended up changing it out for a the new one.
 
i really dont even have to pull the drain plug now. i use the adapter connected to the top of the strainer and flush the whole raw water side with antifreeze. works like a charm.
51FNLPcQ5aL._AC_SL1000_.jpg

https://www.amazon.com/Trac-Ecologi...8627&sprefix=sea+strainer+ada,aps,352&sr=8-14
 
Storm, if you don't first drain the system... how do you know you don't have some sort of "mix" of AF/water in parts of the system? And what concentration is this "mix"... will it be enough to guarantee that your (expensive) system survives the winter?

Are you pumping the AF through or running the engine? It will often be hard to pump it through since you still have to go through the raw water pump and that often seals pretty tight.

Always drain first.
 
OllieC said:
Yup - replaced my cracked one last Spring. Had the notorious slow drip at the blue plug.
Click to expand...
Always use a new high quality o-ring on that plug. Replace it every spring. That’s way it seals up with very little pressure on it.
As the o-ring dries out the temptation is to crank down in the plug to stop the drip that develops. Once it cracks along the casting line, that drip won’t stop.
 
Lazy Daze said:
Storm, if you don't first drain the system... how do you know you don't have some sort of "mix" of AF/water in parts of the system? And what concentration is this "mix"... will it be enough to guarantee that your (expensive) system survives the winter?

Are you pumping the AF through or running the engine? It will often be hard to pump it through since you still have to go through the raw water pump and that often seals pretty tight.

Always drain first.
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mine is a closed system. i do drain first then put plugs back in, run 100% rv AF through with engine running until it comes out outdrive. about three gallons. then remove plugs again.
 
Espos4 said:
Always use a new high quality o-ring on that plug. Replace it every spring. That’s way it seals up with very little pressure on it.
As the o-ring dries out the temptation is to crank down in the plug to stop the drip that develops. Once it cracks along the casting line, that drip won’t stop.
Click to expand...

i replace plug also. they dry rot and break off. and they are cheap, why not. they are pretty easy to get out. easy out doesnt work. use flat head screwdriver. heat up with heat gun and push into plug, then turn out.
 
StormSplurge said:
mine is a closed system. i do drain first then put plugs back in, run 100% rv AF through with engine running until it comes out outdrive. about three gallons. then remove plugs again.
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Yup, I read that you have a half system - it just wasn't clear if you were first draining and wanted to make sure you weren't missing a step. Looks like you got it.

Side note... make sure you are using the proper RV antifreeze (propylene glycol) as the other kind can cause corrosion. And... leave it in so it can keep the insides of the system from corroding. Draining out the "good stuff" offers no benefits.
 
I know this thread is a few months old, but it seems very relevant to a similar question I wanted to ask.

My 2005 320 DA has twin Merc 350 MAG MPI Horizons with the Bravo-III stern drives. I wanted to try tackle the Sea Water Pump impeller change myself so I know what's involved. I've read through a number of postings on how to accomplish this, and believe I have a grasp of what is involved. BUT - I am concerned that simply closing the thru-hull seacock will not completely stop the sea water from coming in once I remove the hose from the Sea Water Pump (similar dilemma to what the OP in this thread had happen). The reason I am concerned is that when I followed the hose from the sea strainer to the water pump I found there is a "Y" fitting just before the water pump. From what I can gather, the second intake hose coming into this "Y" fitting is coming from the B3 drive - is that correct? If so how can I be sure that water won't pour in from it? As has been mentioned in a couple of posts above, this doesn't make sense as it would seem this second intake hose has no filtering being done on it.

Any idea on exactly where this second hose is coming from, and will water be coming in when I remove the hose?

The picture below is from mercury's website, the "Y" fitting is part #42 and it is described as follows:
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On my previous boat that hose went to a freshwater flush on top of the motor.
Follow the hose to see if it goes there.
 
Yes the smaller hose comes from the drive. Water will come in but not with a lot of pressure, A shop rag stuffed into the 1 1/4" hose will work while you work on the pump.
 
As noted, it won't be a whole lot of water. Stuff it/plug it or raise it up high.

The filtering is done by the outdrives intake grate - although it's obviously not as good as a sea strainer. But many, many thousands and thousands and thousands of boats use ONLY the outdrive grate.
 
Thanks everyone for the feedback. I had assumed it was coming from the drive, but wasn't sure. I do have some wooden plugs and shop rags, so I should be good to go now. I guess I'm going to have to stop procrastinating now and get stuck into it! :)
 
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