96 Mariner 115 water flow

[pinellas50]

I need some direction here. I had the family out fishing this weekend. On the way back in we pulled into one of the fingers off the ICW and threw anchor so the kids could swim. When I started the motor back up I happened to look at the tell tale and it had a very weak stream. On the way back to the ramp the stream continued to be extremely weak even at running rpm. It did not overheat.

History: I replaced the entire water pump housing and base plate at the beginning of last season. The motor was peeing like a college kid at a keg party. Prior to the replacement, the pump base was extremely corroded away and leaking badly but it still had a good stream from the tell tale.

I put the motor on muffs and started it. I have water leaking out of every conceivable hole on the lower unit. It's coming out of 2 drain holes and up through the hole where the shift shaft goes. There was no water intrusion into the gear oil.

I pulled the lower unit and.........nothing looks to be wrong. The water pump housing still looks brand new. I don't see how that much water could be leaking from this water pump. I looked up the water pipe into the bottom of the motor and it looked solid.

What am I over looking here? What should I be looking for?

 

[carholme]

Re: 96 Mariner 115 water flow

pinellas50:

Do you have a service manual as the one for your engine should be available online if you have the s/n.

Have you pulled the long water tube and had a look at the condition of the seal 17 in clamp 16 in this link to see if the seal has been crushed. You can pull that unit out for a better look.

http://www.crowleymarine.com/mercury-outboard/parts/360_190.cfm

Gerry

 

[pinellas50]

Re: 96 Mariner 115 water flow

I do have a manual but it isn't a very good one. It's kind of like a Chilton for Mercury/Mariner motors for my year range.

I did not pull that pipe. I would have to figure out how the center section comes apart to get at the pipe and the seal you pointed out. I can see that seal from the inside of the pipe but can't tell if mabey it rotted away or something.

Would hooking a garden hose to that pipe someway tell me anything? Could a restriction in the cooling passages within the engine cause something like this?

 

[carholme]

Re: 96 Mariner 115 water flow

Pinellas;

The service manual for your engine is the same as the Mercury which is P/N 90-830234R04

Here is the online version and if you scroll down the first page, you will see the various engine components in red. Select the one you want, click on it and when the first page opens, click the "Save As" icon in the top LH corner of the page and you can save it to your computer.

http://1manual.com/Mercury manuals/Service Manual PDFs/TwoStroke/830234r3/cover.pdf


Gerry

 

[carholme]

Re: 96 Mariner 115 water flow

pinellas;

Have you owned this engine for long and during that time, have you changed the impeller or had it changed?

Gerry

 

[pinellas50]

Re: 96 Mariner 115 water flow

Thanks for the link to that manual! Wow. It looks like the entire motor has to come apart to get at the top of that water feed pipe. I'm hoping to avoid doing that unless I can confirm something up there is the problem.

I have owned the boat for almost 2 years now. I changed the entire water pump assy: impeller, housing, and base a little over a year ago. The stream has always been fine up until this weekend.

 

[carholme]

Re: 96 Mariner 115 water flow

pinellas;

Well if it quit suddenly like that, I would at least get the cover off the pump and see the condition of the impeller to rule it out immmediately.

Gerry

 

[pinellas50]

Re: 96 Mariner 115 water flow

I haven't done much with this since my last posting. I did pull the pump cover off and the impeller looks fine. It's completely in tact.

One thing I have noticed recently is when starting the engine a hiss noise comes out of the tell tale before it starts to put out water. I don't know how to explain it exactly. It's like air being expelled from the system and the hiss gets constantly higher in pitch until the water show up. Like a kid sucking soda up a straw and allowing air to suck into his mouth at the same time...........you get the sucking noise until the soda reaches the top of the straw. That's the only way I can think to say it. I don't know if this is normal or not but I happened to notice it the last few times I had the boat out. The water flow was fine when I first noticed this so I don't know if that is a symptom of something or not.

My best guess at this point is some sort of restriction in the system. The water pump can't push it's full volume up the tube so mabey it's squirting past the pump to hose connection. There is no sign of that what so ever on the parts but it is the best hunch I have right now.

Anyway..........I plan to pull and replace the thermostat and poppet valve on the motor since that is something I have never done since I have owned it. I was going to try and back flush the motor from the thermostat area while I have it out.


And here is the question. I went to the Mercury shop I deal with all the time and the main guy I deal with wasn't there. I got the thermostat and asked for everything I need to replace the poppet assy. I was given a rubber diaphram for the poppet. I told the guy I was dealing with that I have seen the exploded view of the parts involved and read here that I would need a few different parts for the poppet system. The guy and later one of the mechanics told me all I need to do is replace the diaphram and reuse everything else with the poppet valve.

Does this sound right?

 

[carholme]

Re: 96 Mariner 115 water flow

pinellas;

All the parts you are asking for are readily available for very little cost and yes, you might get away with just the diaphram but you are the buyer. Tell him you want the parts or go elsewhere. You have the parts in front of you so I presume you know the shape they are in.

Gerry

 

[fyrdriver]

Re: 96 Mariner 115 water flow

Hey again...your not gonna believe this but mine does the same exact thing! Are you sure we dont share the same boat?
All of your descriptions to a tee. The hissing sound, the less than what I would call ideal flow, and water out of all areas. Never overheated and water pump assy replaced when I just had it serviced. I didn't replace the thermostat or poppet though. When I asked about them the mechanic said if it aint broke dont fix it...imagine that.
Another thought that may help you, mine did the same before and after the water pump replacement, so its something else. This was one of the two reasons I brought it to the mechanic, you know the other. Ive been fishing it alot and its still kicking(knock on wood).

 

[pinellas50]

Re: 96 Mariner 115 water flow

Haaaaa. Our motors must be cousins or something. My variable rpm and sputtering thing wasn't present on my last trip. Mabey it was bad fuel before or the motor was working harder with more weight in the boat on this trip? I don't know.

With the current water issue. Today I hooked up the garden hose to the water pipe that the water pump feeds the motor through. The tell tale made it's hissing noise then started to produce a little water. The same as it does under operation. No water came down the exhaust dump. After a short time the water hose blew off from pressure. After the water hose was removed water came pouring back out the water feed pipe and a trickle showed up in the exhaust dump.

So I am still going with the internal restriction hypothesis. I never thought to hook up a hose to the water pipe when things were working as they should so I don't know what is normal. Could something as simple as a thermostat cause this?

 

[pinellas50]

Re: 96 Mariner 115 water flow

For the final update. I replaced the water impeller even though it looked fine. I replaced the thermostat and poppet valve diaphram even though they both looked fine. I tried sticking the garden hose into the thermostat hole while I had the stat out in an attempt to back flush the motor. That just got me all wet. I blew compressed air into the tell tale hose to force air backwards through the system. Nothing came out the water pipe.

What I did find was some hard stuff in the fitting that goes through the cowl. This is the fitting the tell tale hose clamps too and water shoots out the other side on the outside of the cowl. I found stuff like hard plastic or something in it. I still don't reall know what it was. I was able to pull it out with some needle nose pliers. I think this was the only real problem I had.

I had the boat out over the Memorial Day weekend for about 5 hours and it pee'd great the whole time.