Water Pump 25 HP Mariner 1994 model

[seeing]

1994 25 HP Mariner water pump issues

I have a 94 25 HP Mariner that looks like brand new probably less that ten hours on motor. While running it the water pee hole would dribble then pump good stream running down the lake once stopped it would dribble pump good stream but just not good stream 100% of the time. So I ordered a new water pump and put it in the old one has a set in the wheel ends from just sitting not running. Now I still do not get a full stream all the time it dribbles then puts out a full stream for maybe ten seconds then dribble then again start to put out a full stream. This was sitting with motor in water at boat ramp. So I brought it home put on water hose and ran a week eater cord up the pee hole and maybe it helped some but it would run full stream then dribble then go back to running a full stream. I held my hand on the motor and it never got what I call hot I could still keep my hand on it after running for a few minutes I just cut it off and need to know back in 94 did the 25 HP mariner put out water like this as being normal. The O ring around where water pump goes was good put some black 3m gasket seal around and put O ring back in place after cleaning around where O ring went. Water pump went into place well just can not figure it out. Big question is this normal do not want to ruin a really nice older motor such as this is. On my Yamaha 25 the pee stream was stead all the time but on this Mariner it is not. If normal O.K. if not tell me where to look to see if I can find the problem. I do not have a book.

 

[racerone]

Does the motor have a thermostat ?----Does the tell tale hose come off the thermostat ?

 

[flyingscott]

That is normal for that motor. The pee-hole is controlled by the thermostat, and depending on water temp will be steadier when water temps are higher and more intermittent when temps are colder . I would make sure you have a 120 Deg thermostat and not a 140.

 

[MH Hawker]

very normal, my 15 hp dose the same

 

[seeing]

As for thermostat I am sure Mercury put one on this motor and I would think not having a book to look at that it is at top where pee hose comes off of. As for what temp it is what ever in 94 Mercury put in it as this motor really looks as if it just was taken out of box and put on boat. To me it looks as if it indeed is thermostat that it is opening up and peeing water them close then open again just looking at how the water comes out. When it comes out it is a strong stream for about 9 seconds then just spits water a little then after about 9-10 seconds here comes heavy stream of water again. The water yesterday out of hose pretty cold where we are near Murphy N.C. Like I said I held my hand on side of motor both sides as it ran so engine was not getting that hot. At ramp before I put it on hose it seemed motor was warmer than here at home. Not sure what lake temp was yesterday but would guess mid to high 50's. I appreciate all your info just did not want to mess up a good motor. I knew what my 25 Yamaha does which is pee water wide open from start to cut off so when this 25 did it off and on it gave me concern.

 

[seeing]

Put new water pump in and it does just like old one it will pee about 9 sec. strong, then just spit a little for about 9-10 sec and go back to pee stream for another 9 sec. is this normal thought water pumps pumped steady stream all the time my Yamaha 25 HP does.
In relation to water pump operation there is a hole just below bolt where lower unit bolts on if you are at back facing front the hole will be below the lower unit bolt near the front side of foot. This hole streams water all the time I had it on hose is this part of the water pump also. Most important is this the way this 94 water pump is suppose to operate ?? I could keep hand on motor and it never got past warm to my hand not sure about in water have not put it in yet.

 

[flyingscott]

Why are you posting this again? You got the answer in your other post everything is normal. I will add one thing you should not have permatexed anything on the water pump. Did you put the rubber ring around the top of the housing.

 

[seeing]

Reason I posted again was just to make sure I did not over look something when I put water pump in and yes I used a gasket seal to put in groove where O ring goes as was told by a mechanic in Alabama that I called. I just have never seen a water pump put out good stream and then stop and spit water then put out stream again and I am going to give this boat to my grandson who has come back from Afghanistan with some feet injury and want to make sure he does not have any problems with boat and motor. Do you know what that hole is top of foot under where you bolt it on that puts out water all the time as motor runs? Is that part of the function of the water pump or something else. Thanks for your help.

 

[flyingscott]

Alright lets do this step by step And thank your grandson for his service for me.
#1 when you replaced the impeller did you use the 2 washers?
#2 you do not need to use permatex on the impeller housing.
#3 did you put the rubber ring over the top of the driveshaft and slide it down to the top of the pump housing?
#4 Did you put the oring on the top of the drive shaft?
#5 Did you put the washer back on the shift shaft so the tilt works correctly?
#6 Did you make sure the water tube is lined up correctly?
#7 The water coming out of the lower unit is normal when you run it on muffs.
#8 The water coming out of the pee-hole that way it is NORMAL as was explained in post #4
#9 If you want your Mercury to pee like a Yamaha Sell the Mercury and buy a Yamaha

 

[seeing]

O.K. yes I did all of the above. Thanks for getting back to me will tell Grandson. However that smart remark number nine was not called for I was just trying to make sure it was working as it should. I have had 200 HP mariners which put our water all the time never had one that did just this but if that is normal then fine he should enjoy it and not have problems. Thanks again for your time.

 

[flyingscott]

The 2.5 litre mecury V6 does the same thing won't pee at all at an idle until either about 1200 rpms or the thermostats open up. #9 was pretty funny.