amount of water on tell tale

[jpen123]

I have a 91 merc 175 efi/xri should there be a constant stream of water from tell tale? I only get good water after it warms up or at higher rpms.

 

[WillyBWright]

Re: amount of water on tell tale

That's what they do.

 

[Texasmark]

Re: amount of water on tell tale

Well you guys, what you are telling me is that the tell tale (Merc used in those days) is dependent upon the thermostat or pressure relief valve being open to function. Not good and in later versions, like my '02 Merc it is there all the time; cause after all it is measuring the output of the impeller, not whether or not your engine is up to temp.<br /><br />Learned the hard way.....Hard Knocks U.<br /><br />Mark

 

[jpen123]

Re: amount of water on tell tale

if that is the case then where would I connect a water pressure guage?

 

[gss036]

Re: amount of water on tell tale

Instructions and parts will come with the gauge. It plugs into the water hose on the top back(rear)part of the motor. The line comes out of the top if there is one, if not there will be a plug screwed into the opening. <br />It should take about a minute or 2 for water to start flowing on the tell-tale. If you run saltwater, you should be checking your thermostats because they tend to build up a lot of salt in the openings, even change the every 2-4 years. Poppit valve should not have much to do with the tell-tale unless it stuck wide open at idle. If that is the case you would most likely be overheating.

 

[jpen123]

Re: amount of water on tell tale

so for a minute or two it will show no pressure on the guage?

 

[KCLOST]

Re: amount of water on tell tale

There should be a plug at the top of the block behind the flywheel, that is the best place to connect on that engine. In my opinion you do not want to tie into the hoses down stream of the t-stats, because until they open you will read zero water pressure. And if they are faulty, the same will happen.

 

[jpen123]

Re: amount of water on tell tale

Thanks KC

 

[gss036]

Re: amount of water on tell tale

The instructions will show schematics and where to connect , just as KCLOST points out. And, there will be water pressure showing before the thermostats open if you hook up as directed. I just did a pressure gauge and new temperature sender and gauge to be on the safe side.

 

[jpen123]

Re: amount of water on tell tale

there is a tap on top of the block with a hose that connects to the poppit valve housing. Would this be a good spot to connect.

 

[gss036]

Re: amount of water on tell tale

YES

 

[jpen123]

Re: amount of water on tell tale

thanks again

 

[jpen123]

Re: amount of water on tell tale

Well I finally got around to installing the pressure guage. Let me tell you it doesn't work as I expected. I only get 7-10 lbs when I'm running about 4000 rpm. I also get zero pressure at idle. Anyone have an answer?

 

[wilde1j]

Re: amount of water on tell tale

Well you guys, what you are telling me is that the tell tale (Merc used in those days) is dependent upon the thermostat or pressure relief valve being open to function. Not good and in later versions, like my '02 Merc it is there all the time; cause after all it is measuring the output of the impeller, not whether or not your engine is up to temp.<br /><br />Learned the hard way.....Hard Knocks U.<br /><br />Mark

Merc telltale's are at the end of the coolant loop (which is why it is a hot stream ) and typically don't start until the thermostat opens, which is typically a minute or two. If the thermostat files to open, you know pretty quick (not telltale) and a hot horn soon after the telltale should start. I don't see any issue at all here.

 

[Texasmark]

Re: amount of water on tell tale

FYI. My '02 90 hp tell tale comes off the top of the exhaust manifold. Has nothing to do with stats/poppet.

My son's '95 150 did come off the stat outputs but you had to wait for the stat to open and that took a lot longer than a couple of minutes and they open and close so it is a poor design from Merc for monitoring water pump operation.

So on his we relocated the hose to the other line (coming from his engine, on top) and now as soon as the block fills up we get a stream. Like that arrangement much better.

Mark