1985 Mercury 50HP 2-Stroke 4-Cylinder

BWR1953

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Jan 23, 2009
Messages
5,802
Time for me to holler for help!

Hi all, I’m installing a used Merc 50 onto my Starcraft Kingfisher. The KF thread is located here.

I have some experience with car engines but not really much with outboards so this is a learning experience for me.


Here are some pix of the engine in question.
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Serial Number 6589696. SN 6589696.jpg


Right now I’m in the process of bringing the motor back to life after it had been neglected by the previous owner(s) for a long, long time. And it’s been sitting unused at my place for 18 months too! I already read the sticky about reawakening a sleeping motor.

Compression is good and the motor does have spark.

I do have this Service Manual. It’s been helpful so far but doesn’t cover everything.
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So far, I’ve removed the lower unit and replaced the complete water pump assembly. I’ve pressure and vacuum tested the LU and it passed with flying colors. Haven’t put it back on the motor yet because I’m waiting for my buddy to help me lift it into place.

Moved on to the carbs and got them removed, disassembled and cleaned up. They were a filthy mess! Today I picked up a couple of gasket sets and a pair of floats. One carb float had fuel in it and I decided to go ahead and get the second float for the other carb too since it was already apart. I’ll start carb reassembly soon. There is an issue with one of the carb float bowls and I'll bring that up a little later.

But at the moment I need help dealing with the throttle shifter assembly. As can be seen in the pix, the PO really did a number on the thing. However, I do have a second identical unit that I can use to get things working. I want to take two broken units and combine them to make one functional assembly for the KF.
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The second unit. ​The shift engage/disengage switch at the top of the throttle lever on the second unit doesn’t work and it doesn’t have a key switch. Otherwise I’d just use it instead of going through the combining process. But here I am. 10.jpg



First things first… how do I get it apart without having springs and whatnot flying all over the place? My manual doesn’t provide any help.

I can see that if I remove screws 1 through 4 that I can get the cables loose. Removing the key switch and front cable connector is also a non-issue. But I’m having trouble removing screws 5 through 7 and am a bit concerned that there may be “something” under the assembly which could sproing outta there!
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And finally, there’s the Allen screw on the bottom of the shifter handle. Does it need to be removed? Thanks!
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Last edited:

BWR1953

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Joined
Jan 23, 2009
Messages
5,802
I mentioned a problem with a carb float bowl. Here's what's going on.

When I removed the bowl, in addition to the crud and varnish, there is a corrosion pit inside the bowl which also appears to be on the outside of the bowl as well. It's visible through the gunk, as are scratches from some prior PO apparently digging around in there. Replacement bowls are no longer available. I've done some searching for a used one but haven't had much success.

The question is; how do I, or should I, attempt a repair?

I've had several suggestions:
  1. Use JB Weld to fill the pit.
  2. Solder the pit on the inside.
  3. Silver solder the pit. (I think that might be too much heat.)
  4. Leave it alone until it starts leaking, then solder the pit from the outside.
I'd like to hear other ideas before I proceed.

Thanks!

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I did a leak test and there was no leakage.
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This is what the pit looks like up close. It's not all the way through, but it's close!
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And here's the corrosion on the outside of the bowl.
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thomas15

Seaman Apprentice
Joined
Aug 13, 2014
Messages
43
There are probably differing opinions on this carb matter but for me personally as long as it's not leaking I would not worry about it until I get the motor running properly and everything else set up. I think the epoxy glue is a better idea than solder but again I would wait on this. You might be able to find a used set of carbs or an old donor motor to solve the problem. Let's see what others have to say.
 

BWR1953

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Jan 23, 2009
Messages
5,802
I do have a line on a parts motor. I'll know more about it tomorrow.
 

BWR1953

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Jan 23, 2009
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5,802
Parts motor deal didn't happen. The guy sold it.

Still looking for suggestions on how to deal with the carb issue.

And my buddy got the shifter controls apart. Having some difficulty getting it back together though! :rolleyes:
 

racerone

Supreme Mariner
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Dec 28, 2013
Messages
36,031
I can not believe that you can not find those bowls in Florida.----They were used for many model years on that motor..
 

BWR1953

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Joined
Jan 23, 2009
Messages
5,802
Couldn't get a replacement bowl for the 32 year old float bowl.

Running out of time so I decided to just go with JB Weld on the outside of the bowl only on the scratches and scrapes. I didn't feel comfortable with putting anything inside the bowl where it could potentially come off and clog things up.

Both carbs are reassembled and ready to remount on the engine.

Moving on to other stuff with the motor. Will be degreasing and cleaning everything then reinstalling the lower unit and carbs.

The shifter control is the big roadblock now. :blue:


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