Draining exhaust risers and (mostly) stripped manifold drain hole

[tango13]

Hi guys, recently winterized my 78' mercruiser 250 (350ci), and I noticed brass plugs on the exhaust risers... I opened them up an water drained out. From what I understood, all the plugs required to drain where the 2 block drains, 2 exhaust manifold drains, and power steering cooler.. This is my first time winterizing. Anyone know about this, can the risers crack if not drained?

Also, my starboard exhaust manifold drain hole is pretty much hooped, the plug basically just sits in the hole and turns when its in all the way but doesnt snug up.. Any suggestions, like should i get this tapped or can i get away with gooping the plug in every time I winterize?

Thanks for your help, I have a bit of boat knowledge but this is my first boat (just got it a month ago) so im still learning lots

 

[04fxdwgi]

You are off to a good start. I would also either disconnect the large hose on the engine coolant circulation pump and drain it or disconnect that hose from thermostat housing and flood it with RV antifreeze. Lots of water sits in there / the bottom of the coolant pump and can freeze, since it's a low point.

The manifold drain plug needs to be a good fit and be able to be tightened. If not, it may come out while in use, which will be very bad. Sounds like re-tapping is in your future.

 

[alldodge]

Hi guys, recently winterized my 78' mercruiser 250 (350ci), and I noticed brass plugs on the exhaust risers... I opened them up an water drained out. From what I understood, all the plugs required to drain where the 2 block drains, 2 exhaust manifold drains, and power steering cooler.. This is my first time winterizing. Anyone know about this, can the risers crack if not drained?

Also, my starboard exhaust manifold drain hole is pretty much hooped, the plug basically just sits in the hole and turns when its in all the way but doesnt snug up.. Any suggestions, like should i get this tapped or can i get away with gooping the plug in every time I winterize?

Thanks for your help, I have a bit of boat knowledge but this is my first boat (just got it a month ago) so im still learning lots

Sounds like you have the original log style manifolds
http://www.mercruiserparts.com/Show...r=60&bdesc=EXHAUST+MANIFOLD+AND+EXHAUST+ELBOW

So draining the elbows is a good idea. Now with the plug just sitting in there and not being able to be tightened up, I would be looking into new ones. They are probably getting thin and is only a matter of time before they give your engine problems. Suggest converting to new style. If you go this route I would also suggest new style thermostat housing and hoses

 

[Bondo]

Also, my starboard exhaust manifold drain hole is pretty much hooped, the plug basically just sits in the hole and turns when its in all the way but doesnt snug up.. Any suggestions, like should i get this tapped or can i get away with gooping the plug in every time I winterize?

Ayuh,.... Welcome Aboard,..... Is it a brass plug,..??

If so, try a new fresh one,.... they do wear with time,....

Btw,... Also pull the Big hose, off the circulatin' water pump,......

It holds enough to freeze the water pump,...

 

[tango13]

Ayuh,.... Welcome Aboard,..... Is it a brass plug,..??

If so, try a new fresh one,.... they do wear with time,....

Btw,... Also pull the Big hose, off the circulatin' water pump,......

It holds enough to freeze the water pump,...

Ill see if my plug with some goop will hold in the spring, and if I have issues Ill try a new plug or try and re-tap the hole.. Thanks for the tip.

In regards to the water pump hose, I was only able to get the top end (which goes onto the TSTAT housing) off, and I pulled it down to try and drain it as much as possible.. It must have been opened up for about 3 weeks (along with every other drain) untill I was able to get some time to change the drive oil and put all my plugs back in. So I was NOT able to remove the water pump side of the hose, as it was stuck on pretty good. Should I be worried about that water in there, even after draining as much as possible from the top of the hose? I currently live quite a ways (3 hours) from where my boat is stored.. Should I try and get the hose off to drain any remaining water? and if so, could I pour a little automotive glycol that mixes with water and avoid damage that way?? (I know glycol is bad for the enviro but I can run the boat on muffs in the spring in a local shop with a closed oil/antifreeze drain)

 

[alldodge]

If you were able to take the top of the hose and move it below the bottom hose connection you should be OK.

If not you can take a small and thin Phillips screw driver and after loosening the hose clamp so its a bit sloppy, push it under the bottom of the hose. The water will start coming out, doing this will drain it low enough so not to worry with what's left.

Otherwise pour some full strength glycol down the top hose, wont need a lot maybe a 10 oz. Or pour a half gallon of RV antifreeze down the hose and let the rest run back out the drain plugs in the block

 

[tango13]

If you were able to take the top of the hose and move it below the bottom hose connection you should be OK.

If not you can take a small and thin Phillips screw driver and after loosening the hose clamp so its a bit sloppy, push it under the bottom of the hose. The water will start coming out, doing this will drain it low enough so not to worry with what's left.

Otherwise pour some full strength glycol down the top hose, wont need a lot maybe a 10 oz. Or pour a half gallon of RV antifreeze down the hose and let the rest run back out the drain plugs in the block

Thanks for the advice!

I think ill pour some gylcol down the tstat housing next time I head home (Im a college student and my boat is 3 hours away at home) and go with that. Im pretty confident that there isnt too much water in the water pump (not enough to wreck it anyways), fingers crossed! Atleast water pumps aren't too bad to change out if I do end up losing it. Plus I suppose a little glycol will keep that block from getting more rusted then it should be..