1958 merc 58a not cooling properly

[jwilkey84]

Well, today I totally tore apart a parts motor just for practice before I tear into the good motor. My impellor is good, but I am still not cooling properly, so I thought I would remove the powerhead and look at the gasket there and also look over the hole where water is supposed to enter the block. Is there anything else I can try to do before I HAVE to remove the powerhead? Is there something that I can force into the water system that might clean it out and remove particles that may be clogging the system? Drano,Peroxide, anything? I really dont want to take the powerhead off, but if that's what it takes I guess I'll do it. Also, does it matter which way the impellor fins are curved when I put it back in? Maybe that could be part of it too. Please help!

 

[Scaaty]

Re: 1958 merc 58a not cooling properly

Was it a salt water motor at one time? I know yer in Iowa, but motors have legs over the years...corrosion will be evident ...

 

[jwilkey84]

Re: 1958 merc 58a not cooling properly

I dont believe it has been in saltwater. I have two parts engines identical to it and it looks the cleanest of the three. I think locals have owned it all of its life. There is a cover on the left side of the motor as you look at the sparkplugs from behind, I took this cover off of the parts motor when I was diesecting to practice, and I think that is where a lot of the water comes into the motor. Do you think it would be a good idea to take that off and take a look inside, just to get an idea of how corroded the inside might be? Or do you think I need to take the power head off and look where the water tube comes directly into the unit? I guess I might check the impellor one more time, but I know that isn't the problem. Also, how do I get below the impellor to replace seals in the lower unit? Is there anything like a solution to use to dissolve any corrosion in the engine?

 

[jebeebe]

Re: 1958 merc 58a not cooling properly

You should use vasoline on the impeller and turn the drive shaft clockwise while pushing down on the houseing to get the fins going in the right direction. I replaced the whole pump on mine and fixed a problem that the impeller didn't. Must have been a crack in the lower houseing or some problem. When I did that it replaced the inner and outer seal at the same time. Pumped much better then. That lower houseing is tough to get out, but if you're replaceing the whole pump you don't have to worry about breaking it getting it out. Good luck................Jerry

 

[jwilkey84]

Re: 1958 merc 58a not cooling properly

I am confused. You replaced the whole pump? I thought the impellor was the whold pump. I have never been any deeper than the impellor. How do I get below the impellor without breaking things? And what is under the impellor? You see, my lower unit also leaks, so I will need to get in there sometime I think.

 

[diaric]

Re: 1958 merc 58a not cooling properly

when you get a full water pump kit, you will usually get a new upper waterpump case, new gaskets, and a plate, and maybe a slinger. the base is usually a seperate item. under the base is the seals for the lower unit, that is where you can get leaks. yours is a little different set up, and i haven't seen the waterpump case parts available, so removal should be done carefully. if you check out this link on old mercs, you can see some of the parts that are available for yours when you go down to waterpump parts.
http://www.oldmercs.com/mark58a.html

 

[jwilkey84]

Re: 1958 merc 58a not cooling properly

Does anyone else have any thoughts on this subject? If not, I'll tear into things.

 

[jebeebe]

Re: 1958 merc 58a not cooling properly

If you get your ser. no. and go to mercuryexpress.com and punch it in, you can find a parts blowup of your pump. That's if they have one that old.

 

[diaric]

Re: 1958 merc 58a not cooling properly

mercury parts xpress doesn't take old numbers

 

[diaric]

Re: 1958 merc 58a not cooling properly

there may be cooling and exhaust passage covers that can be removed and check for blockages. someone with some expierence with these old ones may know.
these are other important waterpump parts, if the old ones are worn, impeller won't work as effiently
http://www.oldmercs.com/28091 water pump liner cup.jpg
http://www.oldmercs.com/20272.gif

 

[mixerjv]

Re: 1958 merc 58a not cooling properly

To dissasemble the water pump cartridge you need the special tool part number 22118, No longer available. There is no other way to get it out without destroying it. There is no easy way to fabricate a substitute tool. Keep an eye on ebay.

The cartridge itself has been NLA for years.

The stainless steel liner 28091 went NLA last year.

Is it really overheating? the pee holes clog up pretty easy on those blocks, but many times the cooling is still more than fine.

"cooling and exhaust passage covers " - I would not remove them unless you have to, every one I have removed of that vintage the bolts break off and create a complete nightmare

"Also, how do I get below the impellor to replace seals in the lower unit?" - First, those early units had poor seal design, and most leak anyway. Make sure you are using a heavier grease like lubriplate 105 not the modern lower unit lubes. DO NOT start to take the lower unit apart without all the special early merc tools needed, including the water pump catridge remover mentioned above, you will not get far and/or end up destroying good parts that are NLA.