15 hp merc

Hey everyone, newb here. I have a 2 stroke 15 horse merc that quit pumping water out of the p hole. I figured it was time for a new water pump. Water pump was fine but I replaced it anyway. My question is , if the thermostat is not working can that stop water from coming out? Its around a 1990 model with shift on the tiller. Thanks

welcome to IDO Ben,remove your cowling and follow the tell tale hose up to its fitting at the top of the motor,remove the hose from that fitting and at where it exits the cowling and run a piece of weed eater string down its full length if you can,if not,try blowing it out with compressed air.

before you hook the hose back up and with the motor in the water or muffs hooked up,run it to make sure the fitting itself is not plugged as it very well could be,if so,clear it with compressed air.

on my merc forty,I have to put a golf tee into the tell tale when I am done using it as down here some sort of leaf shredder bug keeps building a nest in it and plugs up the entire hose clear up to the fitting.

give this a shot and let us know

dido on the clogged tattle tail outlet….. I have seen the water outlet hole plugged many times from a variety of debris

I’ve had Asian Beetles stop the tell tail.

I have the zip tie on my 90 horse Merc just snugged up for when I’m in sand (mostly). I can take off the cover, pull the hose that goes from the water jacket to the tell tail and with a slight puff, blow out whatever is clogging it.

Ok I will give it shot if I can locate that hose. Where does the hose connect at the top? I got a few spits of water from the tell tale this evening and it looks like its got some grease in there.

just follow the hose from the tell tale outlet up to the top of the motor,it will connect to a barbed fitting coming out of the upper water jacket.

The tell tale on my motor looks like it goes right into the bottom of the head. (What I assume is the head) all cast metal.

I just went and looked, can’t find any hoses on top side. I might add this is very foreign to me so I appreciate your patience.

what year is the motor? can you post a picture?? dont remember the hose going into the bottom,even my old twenty comes from the top and it was a ’76 model and every thing after that was connected to a fitting near the top of the motor.

I am wondering if you have a foreign built for merc motor

The serial number is 0d182295. I may have posted the wrong year model.

Ill try an post a pic

irregardless of where it comes out of,try and clear it with compressed air,if as you say,it looks like grease in there,it may be packed full of sediment of sorts or bug eggs,had that happen once and it looked like mustard when it finally cleared itself.

Ok im giving up tonight, ill look over the weekend. Something is stopped up. Thanks for the help.

Im trying to send a pic.

Another.

Sorry they are coming across sideways.

the line with PRC on it looks like it should be your tell tale hose,if I am right,remove it from where it hooks up to the upper fitting and clear it and make sure you have water coming from the fitting as well before hooking the hose back up.

Ok I looked up the serial number and its a 93 model electric start.

What is prc?

Ok I see what your talking about.
That hose goes to the thermostat and goes to the outside of the housing. Not sure what its purpose is.

Sorry, it goes to thermostat housing then to the outside of the casing. Not sure what its purpose is.

Remove this hose and clear it.

Ok ill try that this evening. That’s the last thing I know to check hope that works. Thanks

Ok I checked the tell tale and its clean. I did not try to run it with it off to see if water is running out of the fitting but it looks clean also. I will test that tomorrow.

I have run into blockages that required using compressed air while the motor is running,the tell tale may pass water for a bit and then quit again,blow air back through the fitting a couple of times and see if it will start pumping again,usually only took a couple of times doing this to clear it.

make sure you have the inlet screens covered in water if you are using a barrel or make sure the muffs cover the inlets properly.
if after all of this it still doesnt pump water out of the tell tale,you may have to remove the thermostat housing and see if it is blocked severely behind it,ie,mud,packed sand,etc.

the worst one I ever seen had a small rock blocking the transition between the water pump tube and where it goes into the power head,that one required removing the power head as the rock was jammed in there tight enough I couldnt fish it out with a long piece of wire,only took about an hour and half.
to this day I cant figure out how it got that far,let along past the intake screens.

Ok thanks ill try that. If I can get it pumping ill be back on in here to let you know. Thanks again for all the help everyone.

Water is pumping out of the tell tale but not out of p hole. Anybody got a suggestion , im all ears.

Nm , I never heard a p hole called a tell tale, apparently they are the same thing. Sorry for being thick headed. What is the little hole next to the exhaust hole called? Thanks to all.

sorry about the confusion on p hole or tell tale,or tattle tale,thats what I learned to call it from others here in central iowa many years ago.
as far as the hole you are looking at near the exhaust,do you have a picture of it??

if its what I think it is,it is an exhaust bypass for when the motor is in the water deeper than normal due to back trolling or high waves as you would be creating too much back pressure on the exhaust for it to escape through the prop hub,but cant tell you for sure with out seeing what you are talking about.

I think I know what hole you are talking about now that I thought about it for a minute,I would almost bet it is the cowling drain hole,see if you can push a piece of weed eater string up through it and see where it comes out at.

you should see it come out around the base of the motor if I am right.

I pushed line through that little hole , weedeater line barely fits it. I think its tied to the exhaust hole at the top of the lower unit. If I blow air through it it comes out the exhaust hole right next to it. If I plug the exhaust hole it blows out in the lower unit housing. So it must be something to do with exhaust.