Re: 1976 Evinrude 9.9 conversion to long shaft

[optsyeagle]

How old is your impeller? I have a short shaft 1976 motor of the same model, and I find that when I fire up the motor, all I get is a light spray of water out the exhaust. I also have to put my hand back there to sometimes even see the water or in this case, feel the water. When I run it on the boat, that spray turns to more of a stream of water that moves away from and then towards the midsection of the motor, as my t-stat opens and closes and as my rpms increase and decrease.

All that said, all of the various forms of water spray do seem to decrease over time, as my impeller ages. It is useful because it kind of tells me when my impeller is getting weaker before it totally fails. I have never taken an impeller past 5 or 6 years so I could not say what happens after that, but I definitely can tell the difference in water flow between a brand new impeller and one that is 5 years old. The older one pushes out a little less water.

I have never noticed any big difference in the temperature of the powerhead in either of the older or newer impellers that I have used. I suspect a good working t-stat will compensate for this small reduction in pumping power from the impeller. The t-stat would just stay open longer when the impeller gets weaker.

So if you see some form of spray out the exhaust relief hole you are probably OK to go.