Any Other Alternatives To The Plastic Wing Nut Drain Plugs?

[Rickochet]

I have two 2001 5.0L EFI Mercruisers, Bravo II raw water cooled engines on my houseboat. There are six blue plastic wing nuts on each motor to drain the water for winterization. The two on the block and the one in the cooler are a royal PITA to get to. Even the easier to reach ones are difficult to re-install and easy to cross thread. They are also very easy to drop in the hull and difficult to find.

Are there any other alternatives to these plugs? It would be nice to have petcocks like you have on auto radiators that you only have to open the valve then close it after it is empty.

I am guessing that there are no other alternatives since the blue wing nuts appear to have a strange looking thread but I thought I would ask.

Rick

 

[Don S]

Re: Any Other Alternatives To The Plastic Wing Nut Drain Plugs?

It would be nice to have drains like you have on auto radiators that you only have to open the valve then close it after it is empty.

The big problem with those valves is the fact that if they plug up they can't be cleaned out. You really need to be able to stick a wire in the drain hole and make sure it's cleaned out so things will drain completely.
Those plastic plugs are a pain to use, I've replaced them with brass hex plugs. Then it just takes a socket or a ratchet wrench to remove and install.

 

[Rickochet]

Re: Any Other Alternatives To The Plastic Wing Nut Drain Plugs?

The big problem with those valves is the fact that if they plug up they can't be cleaned out. You really need to be able to stick a wire in the drain hole and make sure it's cleaned out so things will drain completely.
Those plastic plugs are a pain to use, I've replaced them with brass hex plugs. Then it just takes a socket or a ratchet wrench to remove and install.

I have had petcocks in other engines and you can clean them out with a stiff wire.

The problem in replacing mine is that there is an engine antiknock sensor in the brass fitting on the block starboard side that Mercruiser has a warning not to disturb when removing the plastic wing nut from that fitting.

I have found some brass fittings and hex plugs but these seem to be 1/4"NPT.

Does anyone know what the thread size is on the plastic plugs?

 

[Rickochet]

Re: Any Other Alternatives To The Plastic Wing Nut Drain Plugs?

Does anyone know what the thread size is on the plastic plugs?

I found replacement blue plastic wing nuts. Part #22-806608A-1.

One website that carried them listed them at .500 - 13 which I assume is the diameter and threads per inch. Is a 13 a screwball thread?

 

[bigskiohio]

Re: Any Other Alternatives To The Plastic Wing Nut Drain Plugs?

standard thread 1/2-13 same as a bolt

 

[King P.V.]

Re: Any Other Alternatives To The Plastic Wing Nut Drain Plugs?

Over the last few years Mercruiser, as well as OMC and Volvo have changed the style and composition of the block and manifold plugs. When they make 'em small, they don't always allow for 100% drainage. Make 'em bigger and you can't get the big wrench on the head........
Make 'em, out of new-age plastic and you can use your fingers. No tools needed. However, IF, you break it off, the body of ther plug is hollow so an EZ out can fit up and help extract the rest of the offending plug. I've often used a very hot screwdriver, stuck up into the darn thing and it always comes out. As to accessability.... ya, that can very well suc, BIG TIME !!!!! I am a firm beliver that boat designers must build their hulls so that mechanics can do the job. It's obvious that they could care less about the the ability to do good/smart service on their product... Ever try to replace/service a sea-water pump on some of these late model boats?? Sad !!!!