Cracked Evinrude bottom end, JB Weld or no?

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osteospurnum

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Hi and Thankyou for reading this.<br /><br />I have just dropped the botton end on my 1971 Evinrude 40 hp big twin to troubleshoot an overheating problem and have found a hairline crack between the water pump and exhaust area.this would seem a likly cause for a failing cooling system.<br />
P1010018w.jpg
<br /><br />the area to the rear of the crack ( outlined in red)is the water pump area and to the fore is the exhaust outlet.<br /><br />I am wondering if I could if properly prepared use a product such as JB Weld to repair it.<br /><br /> a further picture can be found at<br /> Evinrude bottom end <br /><br />Has any one had any joy with a repair of this sort.<br /><br />Many Thanks and a happy New Year<br />Chris
 
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wilde1j

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Re: Cracked Evinrude bottom end, JB Weld or no?

Has any water gotten into LU? This will give you an idea of how deep the crack is and whether it is just superficial. In any case, I would try to clean out the crack and use JB Weld to repair.
 
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osteospurnum

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Re: Cracked Evinrude bottom end, JB Weld or no?

Hi thanks for the reply<br /><br />No the crack isn't near the gearbox and the large shaft at the rear of the picture is the prop shaft.<br /><br />The crack passes between two areas ocupied by water however one side is the area under the water pump bottom plate(removed) and is open to the pump and the other side (facing viewer)is subject to water and exhaust gases.two areas subject presumably to conflicting pressures.<br /><br />The oil is good with no sign of emulsifying
 
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alcan

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Re: Cracked Evinrude bottom end, JB Weld or no?

Hello Osteo<br />Your crack looks fairly insignificant. I doubt I would mess with it. How ever it will probably get worse over time. A neat job with the JB weld would be an ok band-aid. I don't think this will stop the crack for good. I also don't think this is the cause of your cooling system failure (I could be wrong). I would go ahead and do the routine waterpump service, and test. When your sure every thing else is in order, then worry about that crack. How long will this hold? Probably until your tired of this motor. Only the outboard god knows for sure.
 
FLATHEAD

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Re: Cracked Evinrude bottom end, JB Weld or no?

By the looks of the photo this part looks like aluminum. I am no expert on boat motors but I have alot of experiance on antique motorcycle motors. When you have a crack in an aluminum part like that you would do well to get it fixed as soon as possible. The longer you mess with it the more chance of oil,greese, or other contaminents getting into the metal and making a nice clean repair impossible. If its not aluminum disregard.<br />For what its worth---Flathead
 
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osteospurnum

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Re: Cracked Evinrude bottom end, JB Weld or no?

My Seloc manual has a picture of the area I have the crack in and underneath says:<br /><br />"The web area indicated should be inspected carefully for the slightest sign of a hairline crack. The smallest evidence of a crack is cause to replace the housing because exhaust gases will find their way into the water pump area when the engine is operated when the engine is operated and the boat planing. These exhaust gases will cause the engine to run hot".<br /><br />Chris
 
snapperbait

snapperbait

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Re: Cracked Evinrude bottom end, JB Weld or no?

I would have the area repaired by someone who is a very good welder with much experience in aluminum welding... My 2 cents worth..
 
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osteospurnum

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Re: Cracked Evinrude bottom end, JB Weld or no?

It is Aluminium or somthing similar and may well be contaminated by the exhaust gasses but as you can see is pretty clean and otherwise sits below the water line and unlike a gearbox is not subject to sitting in oil but is surrounded by water.<br /> I am intending to drill through the end of the cracK to stop it continuing and the attacking it with a dremel and grinding the surface and possibly V'ing the crack a bit.<br /><br />Chris
 
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tmcalavy

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Re: Cracked Evinrude bottom end, JB Weld or no?

If you like your Evvy, I would drill two very small holes at each end of the crack to keep it from spreading. Now fill smartly with JB weld. Should last long enough for you to find a new lower end or pump housing. Watch ebay motors or post in classifieds at this site:<br />www.aomci.org<br /><br />Note: I filled a hole in the pan of a dishwasher with JB Weld in the mid-80's...it's still going strong...go figure.<br /><br />TWM
 
OBJ

OBJ

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Re: Cracked Evinrude bottom end, JB Weld or no?

After the repair is made, give it a pressure test. I like to pump them up (the lower unit) to 10 to 15 psi and hold them under water and look for leaks. Easy way to spot them. I agree with alcan, the JB weld repair will probably outlast the lower unit.<br /><br />Jim
 
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alcan

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Re: Cracked Evinrude bottom end, JB Weld or no?

Hi Osteo<br />I guess the point I was trying to make is the fact that this crack is really no worse than the rest of the pump plate area. This sucker could be leaking anywhere around here. While I agree a great welding job would be the best, it ain't worth the trouble. Any other hay-wire job will just make things worse. Just clean it up a little and slap some gasket goo or JB goo to it and let her go.
 
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osteospurnum

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Re: Cracked Evinrude bottom end, JB Weld or no?

Thanks guys<br />OutboardJim how do you pressure test a bottom unit, do you mean the water pump or the entire unit?<br />Alcan I agree it's not worth doing anything particilarily expensive or time consuming I reckon that if I was to get it welded I will propably have to renew the prop shaft seals etc. as they propably get destroyed by the heat. I will however need to replace the water pump as it is a bit far gone. so any repair has to be worth the cost of also replacing the pump and the Thermostat which is missing.<br />Chris
 
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alcan

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Re: Cracked Evinrude bottom end, JB Weld or no?

Hi Osteo<br /> Defenatly worth the water pump and the T-stat. And as I suspected the poor condition of the old pump probably had more to do with the over heat problem than that crack. Although I would monitor the condition of this crack a least annually. The person I would choose to make a weld here could do it and never bother that seal. Some of these folks are true artisans.
 
OBJ

OBJ

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Re: Cracked Evinrude bottom end, JB Weld or no?

Hey Osteo...<br /><br />I made a pressure tester from a bicycle pump. I attached a pressure gauge and adaptor that I could srew into the drain or vent plug hole. Testers are commercially available but are costly and I wouldn't recommend you buying one. You just attach the tester to the lower unit and pump it up to about 10 to 15psi. Usually you will know right away if the seals are good if the unit holds the pressure. I also vacuum test them also as usually the seals are double back to back seals. For this I addapted an auto A/C vac. tester. The easy way out is to take it to the local mech and have him do it. Least you'll have some piece of mind as to wether or not the seals are good and wether or not you want to pursue this project.<br /><br />Jim
 
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Hooty

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Re: Cracked Evinrude bottom end, JB Weld or no?

I'm a big JB Weld advocate and would normally say "fix it with JB Weld" but as acessable as that crack is, I think I would "V" it out and have it welded. A good welder shouldn't have any problem with it at all.<br /><br />c/6<br /><br />Hooty
 
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wishinIwasFishin

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Re: Cracked Evinrude bottom end, JB Weld or no?

g'day Osteospurnum<br /> well mate my 2 bobs worth says you should get it welded and yes I agree with alcan these metallurgest guy are unreal with what they can do<br /><br />cheers mate<br />Daryl
 
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wilde1j

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Re: Cracked Evinrude bottom end, JB Weld or no?

There's absolutely no reason to pressure test the lower unit unless there's clear evidence it's leaking (water in gear oil, loss of gear oil over time).
 
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moose211

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Re: Cracked Evinrude bottom end, JB Weld or no?

clean it out and use west apoxy on it it the best :p
 
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osteospurnum

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Re: Cracked Evinrude bottom end, JB Weld or no?

Thanks guys.<br /><br />Thanks a lot for all your suggestions.<br /><br />I copped out and have taken it to be welded I was quoted 20 UKP which seems pretty cheap so it hardly seemed worth messing around with JB Weld and the associated preperation.<br /><br />Thanks again for all the varied suggestions<br /><br />Chris
 
FLATHEAD

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Re: Cracked Evinrude bottom end, JB Weld or no?

Way to go Osteo. Why fiddle around with it. A small weld job like that cost very little but will give you alot of peace of mind. Unless you LIKE to paddle ;) <br /><br />-----Flathead
 
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