1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

[Moxie]

I was prepping the the old "fiberglassic" for another season on the lakes yesterday, started the motor and it purred like a kitten. However I noticed about a 6 inch crack in the lower unit casing around the propeller. I am assuming there must have been some water in there that froze over the winter. I've seen numerous posts regarding this issue but with all types/brands of motors. I've read everything from using JB-Weld to Brazing Rods to just leaving it be. This boat was passed down to me (third generation) and finding parts for a 68 Merc short shaft isn't going to be the easiest of tasks.

Any suggestions? Thanks in advance.

 

[Maxz695]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

welding aluminum can be done by a professoinal. JB weld is an alternative if done correctly snading both inside and out for a proper bond and letting it set which takes some time before fully cured. then theres the if it isn,t broke (Not leaking oil) don,t fix it. as far as brazing I,m not fimiliar with Bass and aluminum being compatible. Just simple advise from me. hope you get your fix

 

[carholme]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

Moxie;

Your engine is a model:

1500108 MERCURY 1968 50

Parts listing:

http://www.crowleymarine.com/mercury-outboard/437.cfm

If you look under Gear Housing you will see the various p/ns for the available gearboxes and using these, you can search online for the units complete or housings only.

Here is one provider you could talk to for assistance:

http://www.marinepowerservice.com/B.../pickdrive/38146A1/path/ 48425/pickyear/0.cfm

Another:

http://www.crisfield.com/gold/store/Mercury bone yard/index.htm

If you get a new housing, the removal of the guts from your existing unit and installing them in the new housing is not a difficult job but will depend on how you feel about your level of experience and whether or not you want to tackle it.

If you choose to repair the existing housing, either JB or welding, you are probably going to have to remove part of the guts as the repair area will have to be perfectly cleaned, inside and out. Hard to tell you which way to go without seeing the crack. Is it leaking at present? If not and the crack is evident, it is probably going to leak and it will be at the most inopportune time.

Gerry

 

[Moxie]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

Here is a photo of the crack. I can tell you that it is not leaking oil, but I haven't opened the plug to see if there is any in there either......

 

[carholme]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

Moxie;

That will have to be looked at closely as if it is cracked, it appears to pass through the support area for the outer race of the forward gear bearing (item 61) in this link:

http://www.crowleymarine.com/mercury-outboard/parts/437_20.cfm

You hit something pretty good or the LU had more water than oil in it over the winter. First thing to do is remove the drain plug and capture any fluid that drains out, if there is any in there.

This is not a JB weld repair in my opinion and depending on what it looks like after stripping the paint, it may not even be worth repairing but I would leave that decision up to a good machine shop. If it is cracked at the front end where the support for the forward gear bearing is, welding may not even be an option.

Gerry

 

[Wingedwheel]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

I agree with Carholme. I have used the aluminum rods and they work great if you get it hot enough, but thats not something for an amatuer to mess with and even then you still have to disassemble it. Thats a good motor and you can probably find a used LU that would just bolt up for a reasonable price.

 

[Moxie]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

Not the best prognosis...=) I certainly do appreciate all of the info. I don't recall hitting anything, but we sure did have a cold winter. The motor itself runs like a dream -- always has. I can't complain considering the motor is 10 years older than I am... I actually found the same exact motor right in my back yard but I can't get in touch with the guy.... http://maine.craigslist.org/boa/2324422866.html

Thats if I could even get the LU off without destroying it. Looks like it's in rough shape.

 

[Wingedwheel]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

Moxie, search the forum on advice removing difficult LU's. Some look bad and practically fall off when unbolted. Others.....well lets see what you come up with.

 

[Moxie]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

I finally got a call back on the parts motor, going to take a look at it today. Looking at the pictures, do any of you feel that it would be a worthwhile endeavor? I'd hate to buy the thing only to find that it's useless. Anything in particular I should be looking for to determine whether or not the LU (or other parts for that matter) can be used? Thanks!

 

[carholme]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

Moxie;

My old eyes are having a problem with the third picture but it looks like a long if not, extra long driveshaft. Do you know what yours is?

http://www.boatmotors.com/ref/shaft_length.html

This makes a difference if your plan is a direct swap of the LU.

Gerry

 

[Maxz695]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

as long as it,s cheap enough it would be worth just for the LU and parts. Check what the fluids look like in the lu leave open(drain plugs to allow all of the oil water metal whatever is in there out for a long bit.Then check to see if the F N R are good (Full rotation listening to the inside gears. If no water you should be ok with a new waterpump and some new gearcase oil. that crack dose not look to good and I fear in time will corrode through the casing. Is the wiring on the engine in fairly good condition? You can also rebuild those carbs and have them at the ready when needed. being that your emgine has sentimental value and you plan on keeping her in the family. That parts motor can be a blessing to you. Extra drive shaft, extra prop, powerhead, and componants. I guess it depends on the LU condition and what he wants for it

 

[Moxie]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

As far as I know, mine is a short shaft. In the Craigslist ad he claims his is a short as well. You dont think it is? Now that you've pointed it out, it does look longer. Hopefully it's just the camera playing tricks on us. Also, I'm not convinced the entire LU needs to be swapped. I know it's a tougher job, but could just the gear housing be replaced?

 

[carholme]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

Moxie;

Hopefully, it is just the camera and that you are able to get a good housing out of it. Let us know after you look at it. Do you know the s/n of the engine?

Just looked at the listing and if you can get him down on the price, you probably get some decent spares for yours no matter what.

Gerry

 

[Moxie]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

I agree, the parts alone would probably be worth it. I'll probably still try to find a LU, but I spoke to my dad and thinks he may be able to weld the crack shut. He had the boat before me and also mentioned that it needs a water pump. We're talking about a guy that once built a submarine just for fun, so I'm hoping we can at least get a fix in place that will get me through the summer. I'll post an update after seeing the parts motor. It's in the middle of the woods at some camp. Glad I have a Jeep and a GPS -- should be an adventure.

 

[Moxie]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

Moxie;
Do you know the s/n of the engine?

No idea what the serial is, only that it's the same year / same HP as mine.

 

[Maxz695]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

good luck i just fera the heat will distort that crack and make it even worse Just waping the LU would be the easiest solution. I think the camera is inded playing tricks but double check it let us know what this guy wanted for this engine i,m curious

 

[Moxie]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

He is asking 150 for it.

 

[Maxz695]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

Thats a steal if the shaft is the same run run run get that engine!!!!!!!!!! At worse you can redo the casing with your old unit

 

[Chinewalker]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

I concur - worst case scenario, you swap the driveshafts around to get the short shaft on your motor. Regardless, running a 40+ year old motor, it is never a bad idea to have a parts motor in the shed... The one in the pics appears to be a '67.

 

[Moxie]

Re: 1968 Mercury 50HP outboard - Crack in lower unit - best plan of action?

Well, I swung by and ended up talking to the guy for a good two hours. The motor is not a short shaft, but the guts are actually in decent shape and the housing should at least fit my motor. Tried to talk him down, but he threw in a set of controls that are actually in better shape than mine. I've got it out back on the stand. My first impression/concern is that this baby spent some time in salt water..... I'll post some better pics soon.