whats with this nipple?

[neversinksmith]

hey gang. just picked up an old 1973 merc 850 85hp 4 cyl. I noticed that in the middle of the back plate (cyl head) there is a brass fitting that sticks off the engine. is this some sort of vacuum line or does it have to do w water flow? either way it looks like it should have a hose hooked to it. can someone tell me what its for and where the other end of the hose would run to? thanks

 

[gm280]

I tried searching the break down for your '73 Mercury 85HP engine and all I can see is a 90 degree hose type connector part called a Balancing Elbow tube. But I have no idea if that is what you're referring to. If you can post a few pictures of it then we (I) can get a better idea... Or maybe others will chime in with that knowledge already...

 

[Chris1956]

The location described is where the telltale elbow would be located. Some inline Mercs have a second threaded port on the cylinder head water jacket as well. They are usually plugged, but sometimes owners use them to connect to a water pressure gauge.

 

[neversinksmith]

parts breakdown.Mercury Quicksilver 22-32802 2 - Plug - (brass)
but this has a 90' bend in it and clearly is set up for a hose attachment

 

[GA_Boater]

What's your serial number, neversink? Does you motor have a telltale?

 

[neversinksmith]

374657. yes it has tell tail and its hooked up to a line. maybe the p/o replaced plug w this 90' plug for water pressure as mentioned before.

 

[GA_Boater]

Is the other end of the telltale hooked up? On these motors, the telltale hose is connected at one of two places - The nipple in the cylinder block cover like you have or on the port side on top of the block almost under the flywheel. It's been said the one on top of the block is better for cooling because it allows a potential air pocket to bleed off.

 

[gm280]

If it is for the pee tube outlet and you have another one on the top of the engine setup, I'd certainly go with the top one for the reason previously stated....it allows any air bubbles to escape and that allows the water do its job better.. . But if you do use the top one, that one in question would either have to be blocked off or "tee" it into the top. I would think blocking it off would be the better option. JMHO!

 

[neversinksmith]

thanks guys

 

[neversinksmith]

upon closer inspection the line comes from the bottom of the power head, not from the top under the flywheel as stated by GA boater. (this is a 1973 850)

 

[aussieflash]

Wouldnt it be sooooooo much easier just showing us in a pic.

 

[GA_Boater]

upon closer inspection the line comes from the bottom of the power head, not from the top under the flywheel as stated by GA boater. (this is a 1973 850)

You can probably swap the elbow and plug in top of the block if you have one and add a longer hose if you wanted to.

 

[rookie456]

No Title

I am in the process of rebuilding a 1980 Merc 80 hp. I attached a picture of my water jacket cover between spark plug 2 and 3 I have a 1/8 inch pipe plug. Does this look like the area where the nipple is screwed in? I plan on threading a temperture sender there.

 

[merc850]

This is a parts listing from 1975 850 Part 17 or 27 are at the bottom of the block and are bleed check valves attached to a hose that runs to the top bearing, just bought one last week from my Mercury dealer $14.

 

[neversinksmith]

I am in the process of rebuilding a 1980 Merc 80 hp. I attached a picture of my water jacket cover between spark plug 2 and 3 I have a 1/8 inch pipe plug. Does this look like the area where the nipple is screwed in? I plan on threading a temperture sender there.

yes that is exactly where it is. on my 1985 50hp it has a bolt in it like your pic shows. I really like the idea of installing a temp sensor there.
now im just curious why my tell tail line is coming from the bottom of my power head if it should be coming from under the flywheel.
sorry I haven't slapped any pics up. it would make it soooo much easier

 

[rookie456]

No Title

Here are some pics of the bleeders. One fitting at the top bearing under the flywheel and one down by the lower bearing with a hose between them. From what you are describing, it sounds like the bleeders, not a tell tale.

 

[GA_Boater]

Cuz that's the way Merc built it is the simple answer. Why they did it is a Q for the engine designer. :smile:

Do you have the plug on top of the block?

 

[neversinksmith]

so after finishing the new wiring harness and firing her up, come to find out that the line that was running to the tell tail was coming from the port side of the engine directly below the shifting track. however NO water came out of this hose, it came out of the brass fitting on the back of the engine(the nipple) I attached the tell tail line to it and its peeing well. still nothing coming from the lower port side line.
what should I do? do I plug the lower non working line or 'T' it into the working line or is something wrong here or am I worried about nothing because there is water coming out of tell tail?

 

[Faztbullet]

All the older inlines had the telltale off the bottom of exhaust plate. This was then moved to middle then top as it was found out that a weak impeller would show a false "P" stream as the block was not completely filled with water and it would stop up with calcium build up over time(which it seems you have found). Coming off the top ensures block is full before it pee's.....

 

[neversinksmith]

so being that this is a 1973 model, does this mean that I don't have a port at the top of the engine which would be the preferred water outlet and my uppermost outlet would be the one on the cyl cover?