Re: 1984 Evinrude 15 HP, newest motor I’ve ever owned

[Don]

quote pugetsoundboater:

I have a 1976 Evinrude 9.9. Sweet motor! Salt water motor :replaced water pump ,thermostat,cleaned lower unit drain holes (Very Important to prevent water from backing up in exaust housing) ran OMC engine tuner through it. Runs great. I also add 1-2 oz of Seafoam per gallon. ,also flush motor with Salt Away in a barrel after running in salt water. Have fun with that great motor.

The beauty part of the earlier models like yours is that they did NOT suffer with upper grommet problems like the later models.
The design of the water tube and grommet changed in the late 70s, which lead to the headaches. The main problem is that the newer style grommet is not fully supported (ID) by the water tube making the grommet vulnerable to getting mushed over by salt/overheat.
So, I usually don’t change the grommets on the early models unless there is an obvious problem, why introduce a problem. I purposely "mis-install" grommets on the late 70s-mid 80s engines to make sure the ID of the grommet is fully supported. The later 80s grommet/water tube set up was an improvement over the misengineered stuff, but still the grommet was not fully supported. I used to just cut off about 1/8" off the top of the "improved" grommets so the grommet was not taller than the top of the water tube. The last time I bought a new water tube, it came as a kit with a grommet, it appeared to me that they had raised the height of the water tube slightly to minimize the problem.
I wish I had some sort of drawing software so I could do a better job explaining this, because I know a picture is worth about a million of my words.