64 evinrude yachtwin 3hp overheating problem

romanxrs

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Apr 25, 2013
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Bought this nice little motor
Its been siting for few years
So i took the engine apart up until pistons
Cleaned out carb/ all water jackets, the head got all new gaskets new sparkplugs changed impeler triple checked make sure it was installed correctly
But the engine still runs very hot
And there is no water coming out of the 4 toothpick size holes
In few minutes enigune gets so had that it boils and water that gets splashed on either side
Idk what else to check
Please help
 

bonzoscott

Senior Chief Petty Officer
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Jul 26, 2008
Messages
745
Re: 64 evinrude yachtwin 3hp overheating problem

Welcome to iboats! Are you sure the impeller engages? Pull the lower and rig up your garden hose to the water tube. verify that water is coming out the pee hole. While the lower is off, twist the drive shaft (clock wise) and see if you feel the impeller resistance. Don't try and run it any more until you've checked it out. You'll smoke your new impeller.
 

F_R

Supreme Mariner
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Jul 7, 2006
Messages
28,195
Re: 64 evinrude yachtwin 3hp overheating problem

If no water spray out the exhaust relief holes, either the water pump isn't working, or something is plugged up. Sorry, it is up to you to find it, since we can't see/diagnose it from a distance. Let's just say it is not normal for it not to work. They are dependable little motors.

You DO have it deep enough in the water, don't you? Water pump needs to be submerged before starting the motor.
 

MarvK

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Apr 14, 2013
Messages
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Re: 64 evinrude yachtwin 3hp overheating problem

While you have it apart again, check to make sure the drive pin for the impeller is still there and didn't fall out when you put it back together. If you put a new one in, like I did on my '55 Lightwin, it was replaced with a combination pin/key.

Marv
 

kfa4303

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6,094
Re: 64 evinrude yachtwin 3hp overheating problem

These old 3hp make sort of a weak exhaust/pee stream in the first place. Make sure that you only ever run the motor in a test tank, or on the open water as you cannon use "muffs" on vintage motors due to their lack of self-priming waterpumps. Here's a great link that can walk you through a tune up from top to bottom.

3 HP Evinrude Johnson Outboard Tune-Up Procedure 1952-1967
 

romanxrs

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Re: 64 evinrude yachtwin 3hp overheating problem

Yes I only start the motor in test tank and im extra caucious so i fill it up at least untill the toothpick size water holes.
I inspected the impeller around 10 times so far but will check it again today and will try to run the hose thru it
Im almost 100 percent positive that it is something below the engine most llikely lower unit problem because i took block apart and cleaned-blowed commpressed air thru every water jacket to make sure sufficient water flow
 

romanxrs

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Re: 64 evinrude yachtwin 3hp overheating problem

Thank you now i can see how much water suppose to sprinkle out of those tiny holes

When the lower unit is off does that long drive shaft is able to have about an inch or 2 of free play i can lift it up while water pump still bolted on, about 1-2 inches
 
Last edited:

Daviet

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Sep 24, 2008
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Re: 64 evinrude yachtwin 3hp overheating problem

The drive shaft will lift up until the impeller drive pin hits the top of the water pump housing, just push it back down and you will be OK.
 

romanxrs

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Re: 64 evinrude yachtwin 3hp overheating problem

Ok so i took lower unit off double check everything ran garden hose thru sater intake and water came out the water pump hole also when spinned the shaft clockwise it spit out water from the water pump
I also layed motor sideways and ran a hose into that copper looking tube that conects to the waterpump while looking inside with flashlight and water seem to have circulated thru block and came out the other exit hole below the block


Then i made sure the copper tube is propertly conected to the pump when i put it back together

then ran the garden hose thru water intake again and water did not come out thru peep exhaust holes

did a test run again
This time ran for almost 2 minutes before water boiled on block i shut it off immediately
Im assuming this time it ran longer cooled is because there was some water left in the block
When i flushed it

So my conclusion so far is when the lower unit is bolted back together something gets pinched/bent and cuts off water flow?
 

nwcove

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May 16, 2011
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Re: 64 evinrude yachtwin 3hp overheating problem

what did you spin the driveshaft with to get it to "spit" water from the water pump outlet? if you used a drill, it should have shot water out with some force.
 

romanxrs

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Re: 64 evinrude yachtwin 3hp overheating problem

I just used my hand and anytime drive shaft is turning some water would spit out
 

romanxrs

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Apr 25, 2013
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Re: 64 evinrude yachtwin 3hp overheating problem

Also when i do a garden hose test with lower out there seems like a lot of water is coming out from the top of the waterpump where the drive shaft is maybe theres supose to be some sort of seal?
 

nwcove

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Re: 64 evinrude yachtwin 3hp overheating problem

interesting.....from my experience, the ds is always quite hard to turn by hand after a new impeller is installed.
 

romanxrs

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Re: 64 evinrude yachtwin 3hp overheating problem

Yes its hard i used a towel for grip and impeller has some oil on it for lubrication
 

romanxrs

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Apr 25, 2013
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Re: 64 evinrude yachtwin 3hp overheating problem

I might have foun the problem
I made a temporary seal around driveshaft right above water pump and everything seems to work fine now ran 20 min no boiling issue
Am i mising a seal there or simply waterpump housing warned out?
 

F_R

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Re: 64 evinrude yachtwin 3hp overheating problem

Aha!!! As I was reading all those posts about spitting water when you turn the shaft by hand, I was saying to myself "Good Grief".
The fact that it pumps water under those conditions means next to nothing. Reason? Because there is no exhaust in the pump area. If exhaust gets into the pump, it won't work. Now for the Aha!! comment. You asked about a water pump seal. Matter of fact, there is a water pump seal, but not the kind you are thinking about. Look closely at the water pump housing in the area of the outlet grommet. There is a small hole drilled at angle from that area to the cup cast as part of the housing surrounding the drive shaft. Water passes through that hole, keeping the cup full, and preventing exhaust from entering the pump around the drive shaft. You can remove your packing and clear the bleed hole.

Also, along the same note, exhaust can enter the pump below the stainless steel "wear" plate. That plate should be sealed to the gearcase with a suitable sealant.....after you make sure the surfaces are clean and smooth.
 
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