Question on plug plug line on rear of motor

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snookhooked

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This is something I have seen done on other motors but the question is why? Its on the rear of the block. I cant find my manual to research it and don't know what exact name would be used? I had a older mercury motor that it too had been plugged up.

IMG_0763.jpgIMG_0764.jpg
 
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snookhooked

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Re: Question on plug plug line on rear of motor

I guess I am not the only one who doesn't know what its for and if it needs to be fixed. Why its plugged up like it is? I have tried to do research on Crowley motor diagram but it doesn't show both sides to even find a name to research its use.
 
RogersJetboat454

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Re: Question on plug plug line on rear of motor

I'll take a guess...

Is it the water feed to the tell-tale?
 
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snookhooked

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Re: Question on plug plug line on rear of motor

Your guess is as good as mine. its never effect the motor but just curious to why it would be plugged up?
 
RogersJetboat454

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Re: Question on plug plug line on rear of motor

snookhooked said:
Your guess is as good as mine. its never effect the motor but just curious to why it would be plugged up?
Click to expand...


OK... put this another way...
Does your motor currently have a working tell tale?

Hopefully an expert will pop in here, and say it's this or that...
Haven't worked on big or newer outboards to give you a solid answer, but that's my educated guess.
 
classiccat

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Re: Question on plug plug line on rear of motor

i'm also a small OB guy but I like guessing :lol:

1st guess: for monitoring water pressure
2nd guess: for flushing w/out muffs
 
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snookhooked

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Re: Question on plug plug line on rear of motor

RogersJetboat454 said:
OK... put this another way...
Does your motor currently have a working tell tale?

Hopefully an expert will pop in here, and say it's this or that...
Haven't worked on big or newer outboards to give you a solid answer, but that's my educated guess.
Click to expand...

I have always watched to make sure its peeing. I have never really heard the term tell tale to be honest. I replace my impeller every year and never thought much of that tube since everything has always worked fine. It just puzzled me to why and if it needs to have the screw removed that's plugging the hose? I am thinking it must be normal in some ways since it hasn't effected the engine at all to this point. cant really find anything on it through google search.
 
JB

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Re: Question on plug plug line on rear of motor

Do you think you could identify your outboard?? Make, model, HP, etc.??
 
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LongLine

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Re: Question on plug plug line on rear of motor

I'm guessing that insufficient water circulates on one side of that piston, i.e. Maybe it's used to eliminate a hot spot.

Tom B.
(LongLine)
 
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snookhooked

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Re: Question on plug plug line on rear of motor

LongLine said:
I'm guessing that insufficient water circulates on one side of that piston, i.e. Maybe it's used to eliminate a hot spot.

Tom B.
(LongLine)
Click to expand...

Ok, now your thinking that with it being blocked doesn't allow water to use that hose as an exit? I have never felt the motor get hot at all. even while running it, the water may get at best luke warm. Thats feeling the water from the pee hole while running wot. I can let it run on the hose for 30 minutes and the water doesn't get but warm at best. the heads are warm but never been hot. Does this make any sense? I am more curious than anything when asking this question.
 
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boobie

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Re: Question on plug plug line on rear of motor

Somebody maybe had a water pressure gauge on it at one time and then took it off. Pull the hose off, start up the mtr and see if any water pisses out of it.
 
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snookhooked

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Re: Question on plug plug line on rear of motor

boobie said:
Somebody maybe had a water pressure gauge on it at one time and then took it off. Pull the hose off, start up the mtr and see if any water pisses out of it.
Click to expand...

Never would hurt to see. never bothered with it.lol
 
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emdsapmgr

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Re: Question on plug plug line on rear of motor

The normal telltale on that engine comes out of the large rubber (grommet/insert) exhaust relief at the top of the midsection. Think bobbie is correct. In order to plumb a new fitting to drive a remote water pressure guage on that engine, a prior owner has added this nylon hose barb. Since it's no longer used, it looks like that short hose is plugged off at the bottom with a screw and some gasket sealer. As long as it does not leak, it's fine as is.
 
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LongLine

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Re: Question on plug plug line on rear of motor

How about the design engineers really didn't know where the tell tale should exit to prevent hot spot so they had the casting made with two possible places. The old story - casting lead time vs completed testing deadline vs production release - schedule type thing.

Maybe the conversation went like this:

"ah nuts, use the other one." :facepalm:

"But we got this one all drilled and tapped" :eek:

"Just plug it, maybe someone will figure out a use for it one day"

"Yeah, maybe someone will want to put a pressure gauge in it or use it as a flushing port" ;)

"Or go nuts on the internet wondering why it's there & plugged." ;)

"We don't have any plugs with that thread."

"Just put an elbow on it with a hose & barb, this thing's got to be in the showroom tomorrow."



:rolleyes:

Tom B.
(LongLine)
 
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snookhooked

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Re: Question on plug plug line on rear of motor

emdsapmgr said:
The normal telltale on that engine comes out of the large rubber (grommet/insert) exhaust relief at the top of the midsection. Think bobbie is correct. In order to plumb a new fitting to drive a remote water pressure guage on that engine, a prior owner has added this nylon hose barb. Since it's no longer used, it looks like that short hose is plugged off at the bottom with a screw and some gasket sealer. As long as it does not leak, it's fine as is.
Click to expand...

That makes good sense. Thanks guys for the input. I have always been curious to it but everything said makes perfect sense. again Thanks.
 
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F_R

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Re: Question on plug plug line on rear of motor

Parts list shows a "plug, cylinder head pressure tap". Sure sounds like it is for an accessory water pressure gauge, doesn't it?

EDIT: A check shows several accessory water pressure gauge kits offered in 1992. I reckon that answers the question.
 
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snookhooked

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Re: Question on plug plug line on rear of motor

F_R said:
Parts list shows a "plug, cylinder head pressure tap". Sure sounds like it is for an accessory water pressure gauge, doesn't it?

EDIT: A check shows several accessory water pressure gauge kits offered in 1992. I reckon that answers the question.
Click to expand...

Thats good to know. Crowely didnt show much but Thanks.
 
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