1974 Evinrude 115/ one side hot/ one side cold

rkm4

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I've been working on a pumping problem. Now I get the right side hot and the left side cold. There isn't any thermostat. Does anyone know how to make sure the water tubes are in correctly? I also don't see any water coming out the little holes in the back.
 

ezeke

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Re: 1974 Evinrude 115/ one side hot/ one side cold

You have only the one thermostat so the water circuit is either clogged or your water deflectors have moved. Try taking the large hoses loose from the thermostat housing and see if you are getting flow through the engine to that point.

If you don't have a functioning thermostat in place, the pressure will be unequal and result in less than equal cooling in the cylinder banks.

The V4 crossflow engines tend to run somewhat hotter on one side anyway, especially at low RPM.
 

Joe Reeves

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Re: 1974 Evinrude 115/ one side hot/ one side cold

Those small holes you mention..... some engine spit water out them, some don't. This is of no consequence.

The two (2) water tubes...... There are two (2) plastic tube guides that sit in the water pum housing to guide those tubes in place. One guide is slightly longer than the other so that you can insert one tube, then concentrate on getting the other tube aligned.

Those plastic guides work their way up the watertubes after awhile. Look up the tubes, you'll see them if they're there. Hook onto them and pull them off the tubes so that you can use them properly.

The engine requires a thermostat. See the following.

(Thermostat Purpose)
(J. Reeves)

Many engines are considered high performance engines and demand a thermostat(s), and many smaller hp engines also require a thermostat for the following reason. The pistons actually distort/twist off round when running. The thermostat is required to keep the outer wall surrounding the steel cylinder, and the cylinder wall itself at a temperture to compensate for the distortion.

With the thermostat removed, the difference in temperture between the inside the cylinder and the water jacket quickly reaches a point whereas (in effect) you have a oblong piston running up and down a round cylinder, or vice versa. Bottom line is without the thermostat, the piston and cylinder wall could be damaged in a short period of time.

The thermostat in your car isn't there simply to have the heater function properly..... think about it.

And your problem is:

(Water Deflectors)
(J. Reeves)

Water deflectors are actually lengths of 3/8" outside diameter rubber hose, installed between the top cylinder and any cylinder beneath it, and also between the bottom cylinder and the block. The purpose of the deflectors is to have the water follow a definite path around the cylinder walls. Unfortunately the deflectors between the cylinders will at times swell sideways due to either a previous bad overheating problem, or simply due to age and salt corrosion. This causes a water flow restriction which usually allows the water to cool sufficently at low rpms but not at the higher rpms.

This hose material can be purchased reasonably at any automotive parts type store if you care to make your own, or you can purchase individual deflectors at any Evinrude/Johnson dealership at a somewhat higher cost.

Removing and installing them can be a hassle at times, but not always. I use a sharply pointed scribe with about 1/4" of the tip bent at a right angle whereas I can reach in, jab the tip sideways into the rubber, then yank it out. It's necessary to clean the seating surfaces where the ruber contacts the block with a small rat tail file to eliminate salt deposits etc. When installing the new rubber deflector, coat the deflector and the metal surfaces with WD40 which will act as lubrication to allow it to go in as easily as possible.

Make sure that you insert something into that deflector area before cutting and installing the deflectors if you make your own so that you will be certain that they are the right length and also that they will be seated properly. Usually a very small amount will be left extending about the block sealing area..... simply cut the excess off with a single edge razor blade.
 

rkm4

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Re: 1974 Evinrude 115/ one side hot/ one side cold

Ezeke and Joe Reeves, Thankyou, I.m going to try these things You've mentioned You guyts have been great answering my questions i'll let you know how I do. rkm4
 

rkm4

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Re: 1974 Evinrude 115/ one side hot/ one side cold

Hi, Joe Reeves, Where are the rubber water defectors? What do I need to disassemble to get to them and where on the motor are they? I've looked at the cylinder heads but nothing looks like what you're talking about. rkm4
 

ezeke

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Re: 1974 Evinrude 115/ one side hot/ one side cold

The water deflectors are in the water passages on the cylinder banks - click the thumbnail, please.
 

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rkm4

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Re: 1974 Evinrude 115/ one side hot/ one side cold

Does this mean I have to pull off the heads to get to them? You think it's probably the cause?
 

ezeke

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Re: 1974 Evinrude 115/ one side hot/ one side cold

Yes, if the thermostat is in place and working, that's the next place to check. You should definitely want to rebuild your thermostat system first, though.
 

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rkm4

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Re: 1974 Evinrude 115/ one side hot/ one side cold

I just got all the parts for the thermostat. I got all 8 pces, valves, springs, vernatherm, and the 2 gaskets. I'm gonna put them in this week and I'll let you know what happens. It seems these parts are oposolete now, so it was really hard to locate them, but I got lucky. Do the heads have to come off, to get to the water deflectors? Hopefully it won't come to that. Thanks
 

ezeke

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Re: 1974 Evinrude 115/ one side hot/ one side cold

The housing and parts are all in the section just below the cylinder heads shown in the diagram. You will need to disconnect the two large hoses leading to it from the cylinder heads. You do not need to do anything to the cylinder heads to service the thermostat. You may want to remove the exhaust housing rear cover to make it easier to reach the bolts.

Use gasket sealer on the hose fittings when you replace the hoses.

Look carefully at the end of the vernatherm to be sure that it is stamped 105 degrees and not 143 degrees.

You will need to remove the cylinder heads to service the water deflectors if needed.
 

rkm4

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Re: 1974 Evinrude 115/ one side hot/ one side cold

The vernatherm is stamped 105*. I'm on my way out to do it now. I'll let you know soon. Thanks again for all your help. Bob
 

rkm4

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Re: 1974 Evinrude 115/ one side hot/ one side cold

It was a little tricky getting all those things lined up in that small area down there. I got them in, and started the motor, and it worked like a champ. I'm even getting some spitting out of the two holes in the back. The starboard side is still a little warmer than the port side but you said that is normal anyway. You can keep your hand on both sides of the heads without taking them off even when its warmed up. An amazing difference. You surely know your stuff. Thank you so much. I hope you're still out there if something else comes up. I feel as if I should be paying you. If there is anything I can do for you, my expertise is in the home remodeling field. Thanks again Bob:)
 

ezeke

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Re: 1974 Evinrude 115/ one side hot/ one side cold

I'm glad that worked out for you. I used those 1970's V4 motors for many years and did my own maintenance, so now that I have the time to help others with the same problems, I am happy just to be of some help.

I think the best thing about this forum is that so many good people are willing to try to help others, often without thanks or feedback at all.
 

Joe Reeves

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Re: 1974 Evinrude 115/ one side hot/ one side cold

(Water Deflectors)
(J. Reeves)

Water deflectors are actually lengths of 3/8" outside diameter rubber hose, installed between the top cylinder and any cylinder beneath it, and also between the bottom cylinder and the block. The purpose of the deflectors is to have the water follow a definite path around the cylinder walls. Unfortunately the deflectors between the cylinders will at times swell sideways due to either a previous bad overheating problem, or simply due to age and salt corrosion. This causes a water flow restriction which usually allows the water to cool sufficently at low rpms but not at the higher rpms.

This hose material can be purchased reasonably at any automotive parts type store if you care to make your own, or you can purchase individual deflectors at any Evinrude/Johnson dealership at a somewhat higher cost.

Removing and installing them can be a hassle at times, but not always. I use a sharply pointed scribe with about 1/4" of the tip bent at a right angle whereas I can reach in, jab the tip sideways into the rubber, then yank it out. It's necessary to clean the seating surfaces where the ruber contacts the block with a small rat tail file to eliminate salt deposits etc. When installing the new rubber deflector, coat the deflector and the metal surfaces with WD40 which will act as lubrication to allow it to go in as easily as possible.

Make sure that you insert something into that deflector area before cutting and installing the deflectors if you make your own so that you will be certain that they are the right length and also that they will be seated properly. Usually a very small amount will be left extending about the block sealing area..... simply cut the excess off with a single edge razor blade.
 
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