79 Evinrude 70 Cooling Question

[ratherhunt]

Hi,
I just bought a Evinrude 70 horse I think its a 1979 but not sure, when I start it on earmuffs water does not come out of the exhaust in the center of the prop its black and sooty should water come out on earmuffs??. There is warm water coming out of the lower unit in the front towards the stern but thats about it I think there was a water mist comeing from the 2 small exhaust ports on back of motor below the powerhead, I shut it down right away but just hope it was not damaged before I got it. I am going to replace the water pump but I just want to know where water should come from.This motor has no tell tale so I will be adding one after reading posts on here. I hope I can just drill and tap a hole and not have to remove the cylinder head for the tell tale. Thank You for your help

 

[rolmops]

Re: 79 Evinrude 70 Cooling Question

The good news is that your engine is getting cooling water through the block,or the water would come out as cold as it came in.
The bad news... is not really all that bad.
It appears to me that when the lower unit or quite possibly the mid section was taken off,the connections to the exhaust housing were not properly reattached,or just maybe,there is a small hole in the exhaust housing .
The best you can do is getting yourself a factory manual and take the mid section and lower unit off and just check them for any sign of trouble.
This is really not super involved and if you are a shade tree mechanic you should be able to do it by yourself,with the help of a good manual.

 

[ratherhunt]

Re: 79 Evinrude 70 Cooling Question

Rolmops, where should water come out at should it come out of the exhaust with earmuffs on there is only dry soot. I have not taken it apart but your saying that at sometime it was not properly reassembled. At least it soulds like the motor is ok Thank You very much for your help.

 

[billy4hp]

Re: 79 Evinrude 70 Cooling Question

Rolmops, where should water come out at should it come out of the exhaust with earmuffs on there is only dry soot. I have not taken it apart but your saying that at sometime it was not properly reassembled. At least it soulds like the motor is ok Thank You very much for your help.

Well I have a 1978 70hp so I hope I can help...

When mine is running on the muffs, water comes out the tell tale (if you have a 1978 or 1979 70hp the tell tale is supplied by water coming out the exhaust cover, if you have no tell tale then yours is pre-1978)....

If the engine runs long enough that the thermostat opens up, warm to hot water will come out the cheese-grater looking holes on either side of the leg above the anti-ventilation plate and (if rev'd slightly) water will burp out the the two slots that are just below the engine cover cowling...

On the muffs, it is normal to have some pressurized water from your muffs squirt out the front of the leg where the the lower unit bolts to the mid-section.. This water should be whatever temperature it comes out of your tap at...

No water should come out of the center of the prop, that is the main exhaust discharge... When you remove your lower unit to replace your water pump impeller (hint hint) you will find that the exhaust has a seal that should prevent any water from getting into the exhaust stream... If you are getting water out the center of the prop, this seal has probably failed... It is not uncommon to get a sooty drip out the center of the exhaust as this is unburnt fuel and oil...

As far as adding your tell tale, you can drill and tap without removing the cylinder head, just take your time...

Since it sounds like your doing your own maintenance and repairs, do yourself a huge favor and search eBay for an OEM service manual (I bought mine for $30.00)... It has all the information you will likely need, is very easy to read and even has a color flow chart cooling / water flow...

HTH and welcome to Iboats...

 

[ratherhunt]

Re: 79 Evinrude 70 Cooling Question

[I am going to replace waterpump this weekend. Thanks for all the help