How to find the drain plugs on my engine?

[babikov]

Hi,

My question is how to find the drain plugs on the water cooling system of my engine and to make sure that I did not miss one? This is for winterization, of course.

The engine is 1993 4.3LX/V6 Alpha One Thunderbolt Ignition, serial number OF0244564. The transom is OF058634. The drive is OD886515.

The service manual (#14) does not describe this. How these plugs look like and how many of them are there? Are there photos or drawings available somewhere? Any description (like the maintenance manual)?

Thank you for your feedback.

 

[tractoman]

Re: How to find the drain plugs on my engine?

Yep, draining instructions are in the maintenance manual. Photos also.

 

[babikov]

Re: How to find the drain plugs on my engine?

Thanks, but any info on how to find the maintanance mannual for the 1993 engine?

 

[Bt Doctur]

Re: How to find the drain plugs on my engine?

http://www.boatfix.com/merc/Servmanl/18/18covr2.pdf
try in here 6A-14

 

[babikov]

Re: How to find the drain plugs on my engine?

Thank you! This engine model looks very similar to the one my boat has.

So, it looks like there are only TWO drain plugs, one on each side of the motor, at the bottom of cylinder blocks. The rest is drained by disconnecting not the plugs but FOUR hoses: exhaust manifold to thermostat (on each side), water circulating pump to the thermostat, and one house from the power steering fluid cooler.

Is this correct? I am, perhaps, extra suspicions, but after everyone talking about finding all the drain plugs on the engine, finally, I learn that actually there are more hoses to deal with then plugs.

So, let me know please, if this is indeed the case. And thanks for all your help!

 

[Chris1956]

Re: How to find the drain plugs on my engine?

There are two drain plugs on a V engine. One on each side of the block. The manifolds have at least one drain plug each. If the boat has power steering (most do), the power steering cooler located in the raw water pickup hose from the OD will have water in it. So drain block and manifolds. Dump AF into each hose on the block, and see where the AF emerges. When you have AF emerge from a drain, insert the plug and continue to fill until it emerges from some other place, indicating it is full. You will get AF out the water intakes, after the PS cooler is full, and AF out the prop after the manifolds are full.

 

[babikov]

Re: How to find the drain plugs on my engine?

Chris1956,

Thanks for your instructions. One more question.

I found two more hard-to-reach drain plugs, on the outside of each exhaust elbow (lower part of it). These are indeed the drain plugs, they are shown as (a) in the first picture on page 1B-26 of the manual #18 (undrer Maintanance, Draining). So, should I also remove these plugs?

The strange thing is that this page describes draining of the CLOSED cooling system, while my engine has an OPEN system (positive). Draining the open system is described on page 1B-22, but there these plugs are not shown or mentioned.

Any opinion about this puzzle?

 

[fuzzybob]

Re: How to find the drain plugs on my engine?

babikov, welcome to iboats. It looks like we have the same engine/ drive combo. I live in NE Wa St. and the fishing is good in the fall... I end up draining my engine many times before "hard winter" sets in. I use the exact same method you outlined in post #5. I carry a 9/16th ratchet wrench for the block drains and a 1/4 drive ratchet some extentions and a socket for the hoses. I drain as soon as I pull the boat up the ramp. Be sure to lower the outdrive and let the water drain out of the lower end. I also shake out the PS cooler. I don't use any antifreeze and have never had a problem doing it this way. Best of luck and happy boating.

 

[babikov]

Re: How to find the drain plugs on my engine?

Fuzzybob, thanks for your info.

I am new to boating and will be draining/winterizing it for the first time. Just making sure that I will not miss a plug.

Did you see my post #7? Do you have those two "extra" plugs on your engine (on exhaust elbows)? Do you remove them?

They are pretty high up and I guess they are not really nesessary to remove. The elbows are probably well drained by removing houses. What you think?

Thanks!

 

[Chris1956]

Re: How to find the drain plugs on my engine?

On some closed cooling systems the risers are raw water cooled and the manifolds and block are inside the closed cooling system. Those plugs on the "elbows" are likely to help drain the risers. On an open cooling system, and water in the risers can flow thru the gasket to the manifold, and out the manifold drain.

 

[babikov]

Re: How to find the drain plugs on my engine?

Chris,

One more question. When you say ?Dump AF into each hose on the block?, do you really mean all six of them? Should I really disconnect all six? The manual advises disconnecting only one of the six hoses from the thermostat hosing, the one going to the pump. By pouring AF into this house I can fill the pump and the engine block, but not the exhaust manifolds (this is my uneducated guess). So, do you recommend disconnecting more houses? Which ones? Going to exhaust elbows, or to the bottoms of the manifolds?

Thank you.

 

[Chris1956]

Re: How to find the drain plugs on my engine?

I always did all six. Since the risers are connected to the manifolds, you could probably skip either the riser hoses or the manifold hoses. However, I was concerned that some water might sit in a low spot in the risers, so I dumped some AF down them.

You must do the large water pump hose and the raw water hose, so that means at least four of the six hoses.