merc 9.8 not peeing checked everything

C

ctoshack

Cadet
Joined
Sep 9, 2009
Messages
21
Ok here is the situation.... Last fall I changed the impeller and the motor was peeing but not a steady stream and would turn to steam regardless the season was over and I put it away. In an effort to make her pee good again, I pulled the bottom end off and replaced the water pump housing I also took off cover number 29 which you can see here (( http://www.jbcycle.com/fiche_section_detail.asp?section=1305824&category=Outboard%20Motors&make=MERCURY&year=0&fveh=36378 )) to be able to clean the passage ways good. I used compressed air in the watter passage ways with the flush screw out and seen all kinds of stuff coming out the hole. I blew air in multiple ways different directions from the flush hole up the water tube in the foot and threw the passage ways until it I thought it was all real clear. I put everything back with new gaskets and seals and put the foot back in put it in water and started her up.


NO PEE IS COMING OUT BUT THERE IS LOTS OF AIR COMING OUT. I've pulled the bottom end off again to see if maybe I missed the water tube and put it back making sure it was in. I tried again and still not a drop. I took it apart again and checked the impeller this time to see if it was on the key and it seems alright, and now it's sitting apart and I haven't a clue as to why it won't pee.. :confused:

Also while the foot is off I have blown air up the water tube in the foot and I can feel it coming out the pee hole.

What the heck can it be?
 
J

Jacket4life

Petty Officer 1st Class
Joined
Apr 22, 2010
Messages
382
Re: merc 9.8 not peeing checked everything

One: Noticed in your original description, that when you ran it last year, the water would turn to steam in the tell-tale. That is a sign of thermostats being bad. Doesn't really solve ur prob, just letting you know.

What year is this motor?

How are you running it? I.E. in a bucket, on muffs, or (hopefully not) dry?
 
C

ctoshack

Cadet
Joined
Sep 9, 2009
Messages
21
Re: merc 9.8 not peeing checked everything

This motor has no thermostat it seems to have a spot for one but there has never been one. When i read the micro fiche for parts it says that some had thermostats and some did not.

Last year I was using a bucket which I can't find anymore and I don't have a muff for that motor, so I have been taking it down to the lake and putting it on a saw horse into the water. It's seems to be in the water deep enough I just don't understand why it's not peeing. Not even a little bit. I feel lots of air coming out the pee hole and I have blown compressed air from the bottom foot tube and feel it coming out the pee hole as well so I know there is a connection from the feeder tube to the pee whole. Only thing left to me is the impeller and that is even new and is properly seated over the key. There is also a new top housing on the pump so i just don't get it.
 
J

Jacket4life

Petty Officer 1st Class
Joined
Apr 22, 2010
Messages
382
Re: merc 9.8 not peeing checked everything

O.K. How long did you let it run, and only at idle? The reason I ask is b/c it takes mine 45secs to a minute for ANYHTING to come out. And when it's just idling, it still doesn't put out much more than a dribble. But when I open it up, it sprays like a fire hose. Since you are in a decent size body of water, it should work. Just make sure the water is covering the intakes (I always use the cav plate as a landmark for depth) and try giving it some throttle. Put your hand on the cowling, if it starts getting hot, shut it off. But if you feel air coming out, it is most likely going to start peeing you just have to wait on it. I know I was REALLY nervous the first time I started mine after my first impeller job, and it seemed like it took forever. It was really about 1:45 or so. I was about to shut it off and boom, out came the water. But like I said, mine still just barely dribbles at idle.
 
C

ctoshack

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Joined
Sep 9, 2009
Messages
21
Re: merc 9.8 not peeing checked everything

I guess I'll put it back together and let it sit longer, I can't say for sure how long I left it but I don't think I let it run for a full minute. I know I did shift it into gear forward and reverse to see if she shifted right but I didn't let her run to long. My buddy is bringing me a barrel tomorrow so I'll drop it in there and let it run for longer while monitoring the temperature with my hand on the motor. I really didn't thing it would take that long for the water to flow through most motors I've had experience with usually start peeing fairly quickly especially for the fact that there is no thermostat inline I would think it should fill fairly fast and just start peeing.
 
J

Jacket4life

Petty Officer 1st Class
Joined
Apr 22, 2010
Messages
382
Re: merc 9.8 not peeing checked everything

Keep in mind that you fill the entire passage with air, first of all and the impeller has to "seat" itself, then start pushing water, Then it will fill ALL the passageways before it begins coming out of the tell tale. I THINK you are going to get a pleasant surprise.

If you are in a bucket, keep your RPM's below 1500, a bucket DOES NOT simulate a load. (The cavitation will cause the motor to periodically "suck air" and damage the impeller.)

The reason I told you to rest your hand on the cowl is b/c it should NEVER be hot to the touch when running if the cooling system is operating properly.
 
H

huntin dawg

Petty Officer 2nd Class
Joined
Nov 12, 2009
Messages
197
Re: merc 9.8 not peeing checked everything

You said you changed the exhaust cover gaskets. Sounds to me like the exhaust baffle plate is warped, the cover is warped, or both and you have exhaust leaking into the cooling system and vise-versa. Check to see if the baffle plate is warped and more importantly the cover plate is clean and flat. You can clean it up and even it by laying some 120 grit wet/dry sandpaper on a flat surface and working the plate in a figure 8 on it to sand it clean. Also be sure you torque the bolts correctly and in the proper sequence.

Good luck.

HD
 
C

ctoshack

Cadet
Joined
Sep 9, 2009
Messages
21
Re: merc 9.8 not peeing checked everything

I noticed that when I had it off the plate was slightly warped not exactly flat and I thought that when you put the cover on it would flatten out. Can i flatten it out or do I need a new one.
 
H

huntin dawg

Petty Officer 2nd Class
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Nov 12, 2009
Messages
197
Re: merc 9.8 not peeing checked everything

ctoshack said:
I noticed that when I had it off the plate was slightly warped not exactly flat and I thought that when you put the cover on it would flatten out. Can i flatten it out or do I need a new one.
Click to expand...

You can probably get by without a new baffle plate. The cover plate is more important to make sure it's flat. I have a 1973 7.5 HP that's basically the same exact motor as yours. The cover plate on mine was very uneven and took a lot of sanding as I described to get it flat and even. The work paid off because it stopped the leak. It just won't torque down flat if it's uneven at all. Also check the mating surface on the head. I used a long file to clean and even the suface on the head. Be careful to only remove enough material so the surface is flat and even.

HD
 
C

ctoshack

Cadet
Joined
Sep 9, 2009
Messages
21
Re: merc 9.8 not peeing checked everything

ctoshack said:
I noticed that when I had it off the plate was slightly warped not exactly flat and I thought that when you put the cover on it would flatten out. Can i flatten it out or do I need a new one.
Click to expand...


When I say warped I mean in the middle of the plate area not along the edges.
 
C

ctoshack

Cadet
Joined
Sep 9, 2009
Messages
21
Re: merc 9.8 not peeing checked everything

I never took the head off yet, I guess I'll remove the side plate again and check to see if its flat.
 
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