Year of Mercury outboard, pump problem?

[InveraryBoater]

Hi all, just started this run ...

Two questions:

1) I have an older Kiekhaefer Mercury 50 HP outboard with Thunderbolt ignition (Mercury in white lettering, red stripes above and below the logo). I think that it is a 1978 or 1979 motor. Serial # is 3015656. Can anyone tell me the year for certain?? Saw a previous posted site for this, but I don't speak Swedish ...

2) I have been running the motor with the water muffs on it in the driveway and the water pump discharge ports aren't firing out any water. Shut it off and I get some steam/light smoke discharge. Haven't run it for more than 3-5 minutes - just curious if the pump should be picking up this water supply and discharging it normally. I'm thinking the pump may be fried/stuck. Do the water muffs put enough through to discharge out? Or do I need to put it in the water and see how it goes ...?

Thanks ... learning ...

 

[InveraryBoater]

Re: Year of Mercury outboard, pump problem?

Just got off the www.oldmercs.com website and it said that I have a 1971 Mercury by the serial number on the clamp assembly.

From website: Serial numbers 3008819 thru 3176682 were 1971 models.

How accurate is this??

 

[Scaaty]

Re: Year of Mercury outboard, pump problem?

Pull the lower and do the impeller, NOW, then get back if a problem..

 

[LORDY611]

Re: Year of Mercury outboard, pump problem?

My 40hp 4 cyl on muffs will show tell tale stream very quickly, and that's with an impeller that is at least 5 years old (bought from a guy who didnt use the motor, and before I replaced it). The manual says that you dont need a forceful supply of water thru the garden hose. I forget the exact phrase they used, but something like "...only a modest amount of water should escape the muffs when the motor is running", meaning to me that the motor will take what it needs, assuming you are not just feeding it a trickle.

 

[InveraryBoater]

Re: Year of Mercury outboard, pump problem?

Okay, lots since last post, so here goes ...

Bought the Seloc manual for my 71' Mercury outboard, removed lower unit okay, took the water pump casing off, found impeller in not too bad shape ...

The pump casing looked like it was for a high pressure water pump, but the impeller looks like a high volume impeller instead - will check with the marina when I get it over there, possibly had wrong impeller in it??? The impeller looked pretty squashed inside the pump casing - looks too big for the casing to me, but then, I've never had one off before ...

Thought I'd try and see if the rest of the piping and water jacket through to the pee tube was clear, used my hose sprayer on low to push some water up the tube without the pump on it to try and get some water out of the pee tube. No luck - the water went up inside then drained back down. Took the pee tube plastic fitting off at the motor casing and tried to force some water up it backwards into the cooling jacket, no luck there either.

If I'm right, the water line from the pump goes up into the cooling jacket and then exits out the tubing to the pee port on the side - pretty straight forward - what could be blocking this inside?

I'm gonna try and put some 100# compressed air up either way and see if I can dislodge the blockage - friend says it might just be a spider nest up in there, but I doubt it ...

Thoughts ...?

 

[InveraryBoater]

Re: Year of Mercury outboard, pump problem?

Do I have a thermostat in there that just isn't letting the water flow through?? Does it have to get up to temperature in order to allow the water to pass through the cooling jacket?? One website seemed to indicate 160 degrees before the thermostat would let water through ...

 

[jebeebe]

Re: Year of Mercury outboard, pump problem?

The impeller is oversized and difficult to get in to the houseing. This is by design. If an impeller is good when you take it out it will straighten out it's fins. If it isn't it will remain in the bent position. Stiff from age. Impellers are cheap compared to powerheads.
When reinstalling use vasoline in the houseing and turn the driveshaft clockwise while pressing down on the houseing. This will get the fins going in the right direction. Good luck...............Jerry

 

[InveraryBoater]

Re: Year of Mercury outboard, pump problem?

Impeller replaced okay. Thanks for the tip on identifiying a worn impeller. Now for the cooling jacket issue ...

Hooked up a tube with a water valve & a piping clamp to the feed tube for the water pump. Using the valve, I let some water flow up the tube and into the cooling jacket for the motor. Remember that I've already removed the plastic fitting from the end of the pee tube and it is hanging over the side of the motor casing.

The water goes up inside the motor for about 10-15 seconds, then starts running back down around the feed tube for the pump. Used a spotlight to try and see up inside where the leak is coming from, but can't quite pinpoint it - looks like it might be behind the tube at the back of the motor.

Nothing is coming out of the pee tube; tried fishing some wire down it to dislodge debris, but just came back with a bit of grease on the end. 100# air didn't work for much either. When I hooked up the water supply to the pee tube, the line either popped off or started leaking from the base of the motor down underneath.

Am I toast or what? Am I going to have to remove the powerhead and water cooling jacket cowling to get at the problem??? Does anyone have a diagram or something that would show the inlet and outlet of the cooling jacket?

 

[diaric]

Re: Year of Mercury outboard, pump problem?

did you take the water tube out of the powerhead at all? its a connector that does get hard and brittle and can leak
http://www.iboats.com/Mercury_Water....271496--list_time.1185473077--view_id.271508

 

[diaric]

Re: Year of Mercury outboard, pump problem?

you don't have a thermostat, but something could be plugging up water jackets