70 HP Evinrude Cooling

[wrmdunker]

Have a 1974 70 HP Evinrude for 3 years now. New cooling pump and stat 2 years ago by a dealers recommendation.

Running on the muff today to clear the fogging oil and test it pre-launch. Lots of water steams make me wonder how and why this system works. Spot #4 sems to only flow when cold. Had to remove a 2 pc exhaust cover to see what was happeing under it. Perhaps it is not supposed to flow once the stat opens up...???

These pics show the engine idling and a low flow of water from the hose. My biggest concern is the flow at pt#5. Is this normal or has a seal gone bad? Looks the same on port side. I have the OEM manual but not a lot of detail on the cooling system. Motor has no tell-tale but I'm thinking about adding one using the Top Secret Files.

Any thoughts? Thanks.

 

[DargelJohn]

Re: 70 HP Evinrude Cooling

Here is a pic of my old '95 Evinrude 60 running. 1&2 are weep holes that drain the area below the water pump. 3&5 are weep holes that helps drain the area between the inner and outer housings. Can't quite make out where 4 is located.

Yours looks normal. Any overheating problems? Should be able to keep your finger on the head for a count of three.

 

[wrmdunker]

Re: 70 HP Evinrude Cooling

#4 is the highest of the points. I had to remove the cover plates just below the lower motor cowling to see it. I don't think I have an overheating problem based on the driveway test (low RPM, no load, etc.). Again, just wondering how these systems are supposed to work.

 

[wrmdunker]

Re: 70 HP Evinrude Cooling

Still looking for advice.......I'd be happy to run more tests if anyone has recommendations. Since my concern was a the "swivel" (point 5) I should check to see if the water is warm, that would mean it's run through the powerhead.