71 Evinrude Water tube

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Jun 11, 2012
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I've been working (slowly) on taking apart the gearcase. I've read on various posts the it wouldn't come apart easily, but when I took out the 4 bolts the whole lower gearcase about fell on the ground from how easily it came out. Since it came out without me expecting it to, I didnt get to see how the hose was connected (or if it was even connected at all).

So my question is, how is the water tube connected? Mine has a slight angle to it like it was either dry rotted or was ruptured by the look of the edges. But when I look at the diagram http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1971&hp=4&model=4136D&manufacturer=Evinrude&section=Exhaust+Housing it looks like the tube is slightly angled. So if it is slightly angled, does it just fit in the top of the water pump or is there suppose to be some type of fastener to keep it secured in there? Or is it my initial thought of the tube being damaged?

Thanks.
 

Joe Reeves

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Re: 71 Evinrude Water tube

The water tube is a copper tube. The top portion is attached to the powerhead. The bottom portion of the tube simply slides into a rubber grommet in top of the water pump when you install the lower unit.
 
Joined
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Re: 71 Evinrude Water tube

Ha, I wouldve bet my first born son that it was rubber. I literally had to walk down to my basement to look myself and ill be damn it was copper. Sorry I didnt take your word. Still trying to clean all the gunk off. I'm pretty sure Im the first person to open the lower gear case in 30 years. Found larva living inside with gunk that looked even worse than the larva and have ran into 3 stripped screws. Still trying to take apart the water pump without damaging the housing.

Thanks for the input
 

Joe Reeves

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Re: 71 Evinrude Water tube

Best to use a hand held propane torch to heat the aluminum surrounding the screws.... expands the aluminum, helps free the screws.

Suggest however that you do not use a torch in your basement and have a garden hose and fire extinguisher handy just in case.
 
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Re: 71 Evinrude Water tube

Yep thats exactly what I ended up doing. Took it up to my buddys shop to get the last one out of the water pump.

Surprisingly the impeller doesnt look all too bad. It still had all the paddles(?) and were lightly worn. The only thing I could find that was wrong was some of the paddles were firm while others were very flexible. I'm still replacing it along with the lower plate since that was worn and I already have it torn apart. I decided to check the tube just to make sure it isnt clogged and picking up the parts tomorrow so hopefully I can have it back up and running this weekend.

Is there anything else I should be looking for with the water pump? Just want to double check everything before I put it back together and find out its still not working.

And since it did over heat, should I be worried about any internal damage in the block? It didnt seize up on me so I know the piston and cam didnt fry, but I read somewhere else that it could throw off my combustion and/or timing. Is that something I should check for or can I sneak by until this winter when I'm planning on rebuilding the block?
 

Joe Reeves

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Re: 71 Evinrude Water tube

Surprisingly the impeller doesnt look all too bad. It still had all the paddles(?) and were lightly worn. And since it did over heat, should I be worried about any internal damage in the block? It didnt seize up on me so I know the piston and cam didnt fry, but I read somewhere else that it could throw off my combustion and/or timing. Is that something I should check for or can I sneak by until this winter when I'm planning on rebuilding the block?

Very unlikely you hurt anything or that it might require rebuilding. However, check all of the bolts, screws, etc on the powerhead, especially the head bolts. The excessive heat loosens them all.... possible you might need to replace the head gasket BUT if it runs okay and no water enters the cylinders, consider yourself lucky on that point also.

The impeller and plate..... scoring of the plate will kick up an air pocket so it's good you're replacing that, AND replacing the impeller is a must as the slightest wear spells "No Good Impeller". I always replace the entire water pump assembly but I understand the cost thing.
 
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Re: 71 Evinrude Water tube

Thanks youve have been more than helpful with your knowledge. I think I might try my luck with the gasket and see if it will hold up until the fall. Cost does play into it but i'm a firm believer in "you get what you pay for" so i'm definitely not trying to do the cheap fix it route. Just frustrating to buy something then only get to use it twice.

One last question though. Should there be a gasket anywhere in the waterpump? Mine looked like it had resudue of a gasket on the impeller cup and in my mind there should be one. But due to my novice experience with outboards and the vast amount of crap that was built up in it I'm second guessing myself. The diagram I looked at (http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1971&hp=4&model=4136D&manufacturer=Evinrude&section=Gearcase-standard+Drive)only has a gasket in the exhaust cover but I read there should be one under the plate on some site (it was an Evinrude but different hp)??
 

Joe Reeves

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Re: 71 Evinrude Water tube

Nope, no gaskets in the w/pump area. However, it's a good idea to seal the pump housing to the plate, and the plate to the lower unit with the following.

Marprox Sealer 1000 or OMC Adhesive or Boat Armor Sealer 1000 (same substance)[See Below Note] should be used on any metal to metal (Unless GelSeal Is Called For) or metal to plastic surface (such as impeller hsg to plate, and plate to lower unit surface) to eliminate air leaks. It should also be used on the Spaghetti tubing that is used on many powerhead crankcase halves, lower unit skegs, etc. I have found that this substance works quite well on various "O" Rings such as what are found on lower unit carrier and upper driveshaft bearing housings (Note that this substance is obviously not to be used on all "O" Rings). This substance also works quite well in sealing the surfaces between the lower unit and the exhaust housing to which it attaches, eliminating the unsightly water spray between the two after completing a water pump installation.

NOTE: OMC Adhesive is now Bombardier 3M Product #847 .
 
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