Winterizing problem - clogged block drain

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"Project boat" - 1999 Merc carbed 5.7's with Alpha One Gen 2's RWC all but this last season in saltwater.

The port engine went fine, but the starboard engine, is fighting me.

I removed the blue drain plugs from the manifold and block, working from port to starboard. The manifolds drained quickly. I inserted a pick into the block to get the port side of the block to drain. When I got to the starboard side of the bock, no water came out - it doesn't even drip. This is the drain thats's shared with the knock sensor, so I thought it may just be the angle of the fitting, but I couldn't get anything to go in further than about 1"

I asked a local mechanic, and his first suggestion was to remove the fitting from the block, expecting to break the threads on it and re-tap it in the spring. Plan B was to remove the Tstat-to-circ pump hose, fire the engine, give it 3 bumps on the throttle to expel water and back-fill with -200 glycol.

I was fighting a carb flooding issue with this engine, so i don't have the carb on this engine right now. I poured the glycol in until i can figure out what to do.

Any advice?
 
remove the fitting from the block to drain the block. just pouring in A/F does not mix it in the block
 
damn. i wonder what the chances are that the fitting will come out intact.
 
You're talking about blue plastic drains in the block? Why would the threads in the block tear out.

Not sure at the moment where the block drains are...but very few block openings likefreeze plugs and drain plugs line up exactly between the cylinders which might give you a little over an inch. Some only have 1/4" depth before hitting the cylinder wall.

The important thing is the history in salt water and if it was always moored all season long for the last 15 years. There may not be much block left.
 
The blue plastic plug is out, but on the stbd side of the engine, the drain plug shares a Y-fitting with the knock sensor.

This engine is no stranger to salt damage, but the boat has never been wet-stored. She's lived on a trailer and a rack and has been regularly flushed.
 
We have a knock sensor with angled fitting on the starboard side of our 5.7. Advice from this forum was to leave it alone. I can work a bent wire (large paper clip) up in there. Can you make a reverse flush fitting to connect a hose (water or air) and try to pressure dislodge the blockage?
If the knock sensor fitting is brass, it should come out. What shape it'll leave the threads in the iron block is another question.
Thinking about this, I believe I'd like to try and reverse flush that area of the block through the fitting holes.
 
Same exact setup as me, except mine is a '98. Mine was really slow this year but still drained. If you already winterized through your sea strainer, you should already be protected. Some tell me I'm crazy for bothering to remove the plugs after winterizing. If you didn't then you might want to try. Next year I plan on running the engine with the plug out to make sure it is clean. I am going to bring an assortment of #6 through #12 nails bent different ways to poke up past that fitting. I don't want to remove it because I think it's plastic or some composite. If you remove it, let me know how it goes.
 
quote:
Originally posted by j-d

Can you make a reverse flush fitting to connect a hose (water or air) and try to pressure dislodge the blockage?

Click to expand...


I wondered about that. i'd have to play around to find fittings to adapt to the correct thread, but that may be the only way to get to a blockage that's not close to the drain hole itself?
 
quote:
Originally posted by Stephen

I don't want to remove it because I think it's plastic or some composite. If you remove it, let me know how it goes.

Click to expand...


The mechanic I spoke with said it was brass, but on a salty engine, there's no discoloration or patina, so maybe it is plastic?
 
Can you reach down and scratch it with your pick, see if it shows brass?
 
yeah - I wish i had done that while I was still at the boat. Now I have to figure out how to get back and figure this out before the first freeze danger.
 
Would it help if I went out tomorrow afternoon and scratched ours? Can also try to stick a magnet to it.
I don't think plastic would meet MerC's durability standards. Yes, I believe MerC has "some" durability standards...
 
Thanks, but I'm starting to agree that the fitting has to come out no matter what. I think I'll shoot some PB Blaster in there and start looking for the best tool to get in there and get good a good grip on the fitting.

Charlie's damn words kept me up last night.

quote:
Originally posted by jtybt15

The important thing is the history in salt water... There may not be much block left.

Click to expand...


I remember flushing the engines while the boat was still in Florida, I noticed the water flowing from the stbd engine was warmer. I thought it might be just a difference in the thermostats, but the stbd block filling with rust scale fits perfectly with warm discharge water and a clogged drain port.
 
I didn't realize you didn't get the KS out of the block... sounds like they are common to drain problems on this side based on what I've seen on other forums, you're not the only one to experience this.. Hopeful, you have enough glycol in it.. or it don't freeze where you have it.. (might get lucky there) -j
 
It's been awhile and I wondered how this went.

I was working on our boat yesterday. The drain fitting, something like this,
41VtiDsHDJL._SX425_.jpg
came completely out of the knock sensor adapter fitting. I had a good chance to check that fitting. The one that adapts Knock Sensor to Block with a hole for the Block Drain. Definitely BRASS. I scratched it, wire brushed it, and confirmed Brass with a magnet.

VERY awkward to get in there and do much of anything.
 
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