1974 15 hp evinrude water indicator?

[Rope200]

I just bought a 1974 15 hp evinrude and I got it to run well, but I can't find a water indicator and the block seems to get warm when running it with muffs on, I believe it has a thermostat that opens the valve at a certain temperature, is there anyway to test it?

 

[bktheking]

Re: 1974 15 hp evinrude water indicator?

They don't have one, 74-76 never did, 77 on. There should be a couple of exhaust ports at the top of the lower unit looking at the back of the motor, water should spray out of there. The motor has a stat at the bottom of the head, simplest way to test temperature of the motor is with a laser thermometer, anyone who works on outboards should have one in their toolbox. Point it at the block and head while running, my 9.9 runs at 130F all the time. I'd check it with that before pulling the cover off the head to check the stat out, a lot of work to pull it apart if it isn't overheating. They do get warm so touching it with your hand isn't enough to tell. When I put my 9.9 back together the water pump wasn't working, it climbed to 160 so I shut it down, pulled it apart, put another housing on and presto, 130F, they are the handiest things, those thermometers.

 

[the machinist]

Re: 1974 15 hp evinrude water indicator?

These years (1974 thru 1976) only used a "blubber hole" as compared to the later overboard water indiactor that we have grown to be so accustomed to. However if you go back to the start of this section to Frequently asked questions, near the bottom is a link to my 9.9/15 OMC articles. On one of them I cover this

 

[jay mendoza]

Re: 1974 15 hp evinrude water indicator?

With muffs, you have to use quite a bit of water pressure to get the hot water to come out the exhaust releif hole at the top of the mid section. Try tanking the engine instead of muffs and them you should see the water disscharge , it is a spray/mist that comes out.

 

[kbait]

Re: 1974 15 hp evinrude water indicator?

Run it in a barrel, covering impeller housing, and if water mists the hole in back in about 30 seconds, you're cooling. It takes a bit for the thermostat to open and allow water to mist out that hole. And it just needs to mist.. not all the cooling water exits from that port. To test if the waterpump is performing correctly, idle motor as slow as you can (in barrel) for several minutes. If water is misting out that hole, and you can grab the cylinder head for a few seconds, you're all good.