Old(er) Mercury Small Outboard Swivel Bracket Repair ???

[tpenfield]

Hi Folks,

My outboards have been tag-teaming me the past week or so . . .

I recently resurrected my 1969 Mercury 7.5 HP to use on my dinghy, having replaced the water pump and doing a carburetor clean. It ran well but the swivel bracket keeps stiffening up . . . after a bit of usage it seems to free-up a bit so that I can at least steer.

Well after leaving the dinghy (with motor attached/tilted up) for a couple of weeks the steering was more than stiff . . . it would not budge no matter what. I assume the salt water is raising havoc with the steering swivel and binding it up. This has happened in the past, but I have always managed to get enough grease pumped into the swivel that it frees up with some work.

This time it would not move and after several days of working on it, soaking oil into it, heating it, soaking it in rust solvent, applying a power wash (2500 psi) to the exposed swivel joints, etc. . . . It finally wanted to move ever so slightly and now moves with some force required (I removed the steering tensioner pads first thing).

I assume that if I work the thing into submission by working the tiller back and forth it will be OK for a while, but then will 'freeze' up at the next use.

Meanwhile . . . I took my Yamaha 3 HP motor down to the dinghy dock and mounted that up to use while the Merc is 'in the shop' . . . The Yammy worked for a brief while and then crapped out . . . won't re-start for nothing. :facepalm:
Thinking to myself, I'm running out of small outboards, I take the Yammy back home and try to sort that out.

Back to the Merc . . . I'm thinking that I should try to fix the swivel for good so that I can use the motor in the salt water without having to fuss with the steering each time I use it. I've already 'upgraded' the drive shaft on this motor to the stainless steel version for salt water use, so perhaps the steering/swivel assembly is next.

I can get the steering assembly taken apart to about this level, but the swivel pin does not seem to want to come out . . .


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My plan would be to buy a piece of stainless steel tube and fabricate it to replace the carbon steel tube (swivel pin) that is currently in there, but I just wanted to toss this issue out there to see if there is a better approach :noidea:

I was also thinking of using a thick wall PVC tube instead of metal, since the engine is only 7 HP . . .

I could also buy a used swivel assembly on eBay ($150 ish), if all else failed :noidea: However, I bet I would have take that one apart and make it salt water compatible as well . . . so who knows how that approach would work out :noidea:

TIA for any thoughts . . .

PS - Normally, I would just go with the much newer Yammy, but it is only 3 HP and a single cylinder . . . which makes for poor idling, I prefer a 2 cylinder motor over this single cylinder Yammy. My only other OB is a 4.5 HP Johnson long shaft, which is no good for a dinghy . . .

 

[worktofish@hotmail.com]

I'm no expert on this issue, but the idea of using thick walled PVC instead of steel makes me very nervous. I would first find a commercial fastener shop and see what they can do for you.

 

[racerone]

Find a used fresh water midsection.-------Dime a dozen in some areas !

 

[tpenfield]

Thanks for the comments, guys. I can get a fresh water mid-section (swivel assembly) for about $125-150 on eBay. So that will be my 'Plan B', if I end up trashing the original swivel. I'll have to see what I can get for stainless steel tubing to match the diameter of the existing pivot pin (tube) pictured below, which I assume is carbon steel, based on the rusty grease that I have been pumping out of it.



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I've also thought about selling the old Merc for parts and buying a 1990's Merc 8 HP or 9.9 HP . . . it seems like the price of small outboards in the used market has doubled in the past few years. The asking prices are running around $700-800 for 20-30 year old engines.

Not sure I want to go that route (yet), figuring I'd still have to put some money into a 20-30 year old engine.

Meanwhile . . . I dis-assembled and cleaned the carb on the Yammy . . . it runs much better now. I think there was some crud in the fuel and I noticed the engine dies not have an in-line filter coming from the integral tank.

The long shaft Johnson runs fine, when it wants to . . . saving that motor for my sailboat

 

[tpenfield]

Also, FWIW . . . . When I take the swivel / saddle assembly off of the engine, I have been toying with the idea of using a small amount of dry ice inside the swivel tube to really contract it and hopefully break it loose from the 'saddle' piece.

Not sure the pivot tube is a press fit into the saddle. I've seen some YouTube where it is a loose fit . . . :noidea:

 

[tpenfield]

Update . . .

I re-built the carburetor and re-installed it . . .

Got the saddle/swivel assembly off of the engine and now am going to work on seeing if I can get the pivot pin out.



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I am trying some conventional methods first (PB Blaster, CRC Freeze off, heating w/ torch . . . ) to see if there is any hope of getting the pin to move.

I already have a bunch of PB Blaster in the swivel itself (having removed the grease zerk for better access) . . . it initially loosened the swivel up, but overnight it seems to have gotten a bit tighter again

Meanwhile, when I removed the LU, it seems that the new oil seal are not working out so good . . . milkshake oil :facepalm:

The hits just keep on coming . . .

 

[tpenfield]

Quick update . . .

I cut the pivot pin at the lower end of the swivel and tried to get the upper portion of the pin to come loose. It was a no-go so far . . .

Then I decided to focus on the water pump, which seemed to be spewing some gear oil . . . It turned out that the lower body of the water pump did not seat properly in the lower units and therefore was not making a good seal at the o-ring. :facepalm:

I took the thing apart twice to try to get the pump body to properly seat, but for some reason it does not want to. I cannot see anything that would prevent it from seating, but it wants to go in slightly ****-eyed and the fasteners won't get it to seat flush.

This is my first time installing a complete water pump in this engine, so I'm not sure if there is a track to getting the piump body to seat. :noidea:

I don't want to just slap it in and close things up, because it will probably leak again . . .

Not sure why the pump body won't seat, so I'm giving it a rest for the evening and will take another run at it tomorrow.

 

[tpenfield]

Ok . . . there seems to be some mechanical interference with the pump body and the 1980 drive shaft that I upgraded to . . .

The oil seal was bottoming out on the drive shaft flare . . . so I made some adjustments as best I could and pu the water pump back in. The original pump body is NLA and I'm not sure how I came across a pump for this motor . . . I bought ist about 1 year ago . . . .

In other news . . . the pivot shaft is about 7/8" . . . maybe a tad less (08.866 "). So I ordered a stainless steel tube that is 0.840" . . . we shall see how it goes . . .

 

[tpenfield]

Update . . .

I received the stainless steel bar stock that I ordered (actually it is a piece of SS NPT pipe) and re-measured everything with my micrometer.



Existing carbon steel pivot pin measured at 0.873"

The stainless steel material measured at 0.872"

:thumb:

So it looks like I got a good piece of material to fabricate a Stainless Steel pivot pin. Just got to get the old one out of the saddle assembly.

 

[tpenfield]

Some progress to report . . .

I got a few different types of cutting blades in hopes of being able to cut the top part of the pivot pin and free the pivot assembly from the saddle.

A 5" "T" shank metal cutting blade did the trick (hand sawing), and I now have the 2 pieces separated.
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I also made a cut in the pivot pin that is stuck in the bottom portion of the saddle.
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I think I will have to make a second cut in order to free it up. Probably will have to do the same with the top piece of the pivot pin remains. I tried using my 12 ton press, but it did not want to give up easily.

An interesting thing is that the length of pivot pin that is in the pivot assembly was loose at one point, but after sitting a while, (2 weeks) it has seized up again :facepalm: I think the press will be able to break it loose though, since it was recently loose.

Once I get the old pin out, my next step will be to fabricate a new pivot pin out of the stainless steel stock that I have.

 

[tpenfield]

I got the remains of the pivot pin out of the saddle. . .

I had to cut the pin into half-rounds in order to get them to loosen up.


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[tpenfield]

Stainless steel swivel pin . . .

Got it fabricated and did a test insert in the saddle for fit.


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I just got to push (pound/press) the old pin remains out of the swivel piece, and put the swivel and saddle back together.

 

[tpenfield]

Swivel Update . . .

I heated the swivel to loosen its grip on the pivot pin and the 12 Ton press did the rest.
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The newly made stainless steel pin seems to be a bit thicker wall tubing than the carbon steel pin.
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Here is the swivel put together for a test fit . . .


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On to the re-assembly . . .

 

[Scott Danforth]

looking good Ted

 

[tpenfield]

Thanks, Scott

it has been a struggle, but I’m starting to see daylight.

I’m hoping to add some life to this old engine. It would be nice if I can get it to run for a full season

 

[tpenfield]

I got the swivel, saddle, and tiller all put back together and the engine mounted.
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So the swivel is swiveling and the saddle is saddling. Now on to the fuel system and the lower unit.

 

[Laclamoe]

Sorry I don’t know enough about these to help you. But I think you answered my question I just posted about the tiller. Thanks.

 

[gm280]

tpenfield, I guess you proved that idea that ingenuity wins out in the end. I was wondering what type lube/grease you used when you re-installed it all back together again? I was wondering if some type anti-seize would be worth trying since you are dealing with dissimilar metals. I think the stainless steel pin was a good option myself. But ha, what do I really know... :noidea:

Also wondered if you turned a couple grooves in the stainless steel pin so you could use some "O" rings to help keep out saltwater. Glad you got it all worked out again... :thumb::thumb:

 

[tpenfield]

I use marine grease on just about everything . . . There is an o-ring that I installed top/bottom to trap the grease and discourage water . . . although salt water is persistent

I made the fit of the swivel piece loose(er) than original, so hopefully it will hold more grease in between the metal.

 

[tpenfield]

With a burst of energy, I got the Mercury all put back together and running.
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What started out as a swivel repair turned into a bit of a renovation . . .

Swivel repair, carburetor rebuild, water pump impeller, cowl mounting repair . . .

I ran it for about 10 minutes in the bucket, it seems to run well. :thumb: