overheating 15 rude

bluebunnyss

Cadet
Joined
Apr 1, 2009
Messages
10
My 94 15 evinrude has a new waterpump, the tattle tale line is clear, the water intake screen is clrear. It all seems to be in good shape. However, the amount of water exiting the tattle tale is inconsistant...full stream, to a dribble to a drip, and everything in between. As a result the motor gets very hot.
Is there anything else I can check besides the waterpump? A thermostat?? anything?
 

BDbill

Seaman
Joined
Oct 20, 2007
Messages
65
Re: overheating 15 rude

I'd check to see if there is any sand that might have made it's way up and clogged the tube, it happened to my dad's Mercury last year.
 

Rick.

Captain
Joined
Jul 30, 2006
Messages
3,740
Re: overheating 15 rude

The tell tale is to tell you the water pump is pumping not that your motor is necessarily cooling. You should see no interruption in the stream coming from it. It could be a plugged intake or a stoppage in the water tube or a bad impeller. No matter, you must figure it out before you do permanent damage to your motor. Given you have checked most of the above I'm wondering if you got the water tube fitting right in the water pump grommet. Have a look and let us know. Best of luck. Rick.
 
Joined
Jul 30, 2008
Messages
172
Re: overheating 15 rude

Try removing the thermostat, you can check it by heating it in water on the stove. Should open fully before boiling temp. is reached.

I had a similar problem with 1981 15. Pulled the powerhead and gearcase and found disintegrated rubber grommet stopping the water intake pipe on both ends. Result: separated sleeves in both cylinder.



My 94 15 evinrude has a new waterpump, the tattle tale line is clear, the water intake screen is clrear. It all seems to be in good shape. However, the amount of water exiting the tattle tale is inconsistant...full stream, to a dribble to a drip, and everything in between. As a result the motor gets very hot.
Is there anything else I can check besides the waterpump? A thermostat?? anything?
 

jbjennings

Captain
Joined
Jul 18, 2007
Messages
3,903
Re: overheating 15 rude

If checking the grommets and thermostat doesn't cure it, you might have a problem with an exhaust gasket leaking exhaust gases into the water jacket. Are your plugs normal looking or possibly milky or steam cleaned?
I'm curious, did it overheat previously and that's why you changed the pump?
JBJ
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,392
Re: overheating 15 rude

I would check the stats initially.
Why is this thread so wide ????
 

bluebunnyss

Cadet
Joined
Apr 1, 2009
Messages
10
Re: overheating 15 rude

After I bought the motor I noticed the inconsistant tell tale stream. I was advised on this site to change the water pump. Initially it seamed to solve the problem. (When I removed the old waterpump it looked fine.) Then after several open water sessions the same problem began.
The engine was getting extremely hot. In fact when I removed the plugs the metal had changed color due to the heat.
Although the motor ran/runs great all this time.
I have pumped air through the water hose in both directions and it appears clear.
Is it possible that the thermostat is periodically malfunctioning and blocking the water?
If I do need to change the thermostat, how difficult is this? I mean what are the risks of me screwing up my motor?
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,392
Re: overheating 15 rude

May want to run it briefly without the stat and see if it still overheats. Test the stat while it is out in hot water and a thermometer.
 

jbjennings

Captain
Joined
Jul 18, 2007
Messages
3,903
Re: overheating 15 rude

I'm thinking that the tell-tale should still shoot water out fine even if the thermostat were totally closed, so although I'd surely check it like everyone said, I don't think it is the problem. You are wise to find the problem, because if you keep running it so hot, it will surely crater on you. Changing the thermostat is pretty easy, but get a manual or at least look at a parts diagram on shop.evinrude.com or crowleymarine.com so you'll have an idea of what to do.
Good luck,
JBJ
 
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