v-drive drain plug issue

[functionoverfashion]

Winterized my boat yesterday, for the third time since I've owned it. I think the previous two times, I must have drained the v-drive only from the front drain plug (#1 below)





It hasn't been an issue because after draining as much water as possible, I then suck non-tox antifreeze through everything using the "bucket method." But for some reason this year I thought "oh I'll open up the rear drain, too. Which, with the seat back in place, is kind of hard to reach, impossible to see. Well, I turned the plug about 1/16 of a turn and it came out in my hand. I guess it was held in by a half a thread and a little rust, maybe some luck.






I took the above picture blindly - really surprised how well it worked. I could see nothing with the seat base in place.

It's not totally broken off in the hole, but clearly there's a lot of corrosion going on in there, and the plug does look like part of it is missing. I absolutely cannot get a plug to thread back in with it the way it is. So I guess I'll be tapping in new threads (might as well do the front too) and putting in new plugs. That seems pretty straightforward once the seat is out.


However, I am thinking I should try to flush out any bits of metal that result from the thread tapping... any thoughts on that? remove the hoses and just run a garden hose through, letting the water drain out of the bilge? Or is it enough to let the bits get flushed out by normal operation of the cooling system?

[core-rider]

I would try to remove the rest of the plug before going through the trouble of drilling/tapping new treads. An ease out tool should make quick work of that plug. Then you can chase the threads with the proper sized tap to clean out any debris, and replace with a new brass plug.

[functionoverfashion]

Hmm, yeah I guess there's probably enough material left of the plug that I should try to get that out.

The boat is going to the fiberglass shop hopefully soon, for some small repairs. Based on the probable timeline of that, this is looking increasingly like a spring repair. Plenty of time to buy some new tools, like an NPT thread tap set!

[functionoverfashion]

Welp, today I ordered not only a NPT thread tap set, but also $100 worth of adapters and various hardware to put valves in place of most of my drain points. I had my old boat set up that way, and it was so nice not to have to pull all the plugs every time. Flip some valves, get 90% of the water out, then run antifreeze through it all and be done. I'll still drain my heater separately, and the strainer - it needs to be cleaned out anyway - but I can't wait ... till next fall when I actually get to benefit from this.

Skidim used to sell a whole kit for a basic 350 or 351, but the don't anymore. They have quick drains for the exhaust manifolds, but as I was ordering all this stuff elsewhere, I just got all the same hardware separately for less.

If anyone wants a complete list of what I got, I'll definitely share that here. Maybe after I put it all and make sure it works / fits as intended.

[Infinity]

Maybe use a shop vac to pull out as much metal after you tap it....before flushing it?
I use a shop vac against each hole every year as I pull drain plugs, not only to pull out as much water as possible but I figure it also makes sure no debris is blocking the hole and hopefully any rust/scale is being pulled out.
The quick drains are a good idea

[functionoverfashion]

Maybe use a shop vac to pull out as much metal after you tap it....before flushing it?
I use a shop vac against each hole every year as I pull drain plugs, not only to pull out as much water as possible but I figure it also makes sure no debris is blocking the hole and hopefully any rust/scale is being pulled out.
The quick drains are a good idea

The vac is a good idea to have in there while actually tapping it, maybe it would get most of the debris... if I could get it to stay in the right spot. Hmm

And then yeah, I'll probably flush it too.