Water from exhaust

[John Patrick]

I have a 70hp Mercury, 79 model. Should water be coming from my exhaust or do I have a problem? If I do, what is the problem and possible solution?

 

[SpinnerBait_Nut]

Re: Water from exhaust

Merc/Mariner Outboard forum.
Welcome to iboats.

 

[mckeemm]

Re: Water from exhaust

I have a 70hp Mercury, 79 model. Should water be coming from my exhaust or do I have a problem? If I do, what is the problem and possible solution?

I have the same motor and water also comes out the exhaust through the prop. I believe this is normal. The water cools the exhaust. The telltale should have a steady stream when running.

I have a .050" vent hole on the control linkage side of the block that also squirts a bit of water but no one can tell me if this is normal. I posted here this morning and hope to get an answer.

 

[phatmanmike]

Re: Water from exhaust

thats hole in your block is NOT normal.

yes, you have a water cooled 2 stroke , water is SUPPOSEd to come outa your exhaust.

you both need a manual! spend the 30 bucks before you end up with a big black anchor!

 

[mckeemm]

Re: Water from exhaust

Thanks Captain,

I spent fifty bucks on a manual and there is not a damn word in it about the vent I'm talking about. The local marina guys don't know what I'm talking about. I find it very unlikely that the vent hole is only on my motor. Somebody knows what it's for but I'm guessing that person isn't you.

Mark

 

[RubberFrog]

Re: Water from exhaust

Thanks Captain,

I spent fifty bucks on a manual and there is not a damn word in it about the vent I'm talking about. The local marina guys don't know what I'm talking about. I find it very unlikely that the vent hole is only on my motor. Somebody knows what it's for but I'm guessing that person isn't you.

Mark

Well there's a nice polite response that will motivate others to try and help.

 

[bryancx94]

Re: Water from exhaust

mckeemm - why don't you take a picture of it and post it here, will prolly get a better response. You could prolly lose the tude also

 

[phatmanmike]

Re: Water from exhaust

maybe i DO know and im just being a jerk to ruin your day

 

[mckeemm]

Re: Water from exhaust

Ok Ok, having a bad day that day.

My apologies to those whom I have offended. My response was in kind to the assumption that I hadn't consulted my manual before posting here.

I did receive a helpful response to my question on the original string. "merc 70 hp water leaks out vent" suggesting that a water pressure regulator diaphragm under the exhaust cover may be the culprit. This makes sense, as I would expect some sort of diaphragm to be located under the round boss I'm speaking of.

My manual does not contain an exploded diagram of the exhaust cover side of the motor. I have not found one online either. If anyone can direct me to a diagram or list of part numbers for what lives in there I would greatly appreciate it.

Regards, Mark

 

[roger3645]

Re: Water from exhaust

I think that hole on the linkage side is suppose to have a hose connected to it for the pee stream. Does the motor have a stream of water shooting from it when running?

 

[roger3645]

Re: Water from exhaust

Nevermind I see you have a telltale stream.

 

[Silvertip]

Re: Water from exhaust

The poppet valve needs an atmospheric vent for the diaphram to work properly. Water is on one side of the diaghram and air on the other. If the diaphram has a hole in it, water passes through and exits the vent hole. That's the indicator that service is necessary.

 

[technostingray]

Re: Water from exhaust

Thanks Captain,

I spent fifty bucks on a manual and there is not a damn word in it about the vent I'm talking about. The local marina guys don't know what I'm talking about. I find it very unlikely that the vent hole is only on my motor. Somebody knows what it's for but I'm guessing that person isn't you.

Mark

Well there's a nice polite response that will motivate others to try and help.

What he needs is one person who knows, not a bunch a smart alecks that don't. Thanks for being quasi helpful. :duckingthebaragefrombothsides:

 

[ronnieboy]

Re: Water from exhaust

silvertip is right, probably have a bad diaphram. worth checking, this is no place for a adatude or smart axx answer, just try to help, thanks ron

 

[phatmanmike]

Re: Water from exhaust

ray, ray, ray, youve been so full of insight ever since coming on to iboats. thank you so much for all the helpfull hints

 

[Scaaty]

Re: Water from exhaust

Why is this showing up Website/Forum Issues?

 

[mckeemm]

Re: Water from exhaust

The poppet valve needs an atmospheric vent for the diaphram to work properly. Water is on one side of the diaghram and air on the other. If the diaphram has a hole in it, water passes through and exits the vent hole. That's the indicator that service is necessary.

Thanks Guys,

I had assumed that some such mechanism lived under the exhaust cover but could not find any mention of it in my manual or any diagrams. I want to know what I need to fix it before I tear it apart.

Does anyone have an OEM manual with diagrams or Part numbers for the gaskets and poppet/diaphragm assembly?

Merc 700, 70 hp, 3 cyl, (s/n 4571652-4825249) Year 1977