1981 Evinrude 7.5 hp no water prob impeller trouble

[tbarker]

I am new to this outboard motor thing, but I do understand motors in general. My 1981 or '82 Evinrude 7.5 overheated. i only just got it with the boat. Apparantly there was no water getting to the power head. So I took everything to pieces, replaced the rubber grommets at the top of the copper water pipe and put everything back together. Fortunately it started up easily, with the leg in a can of water, but still no flow from the '****' hole. I put a hose on, water flows both ways, up the copper tube and back down when I attach the hose to the rubber outlet hose. There is no thermostat installed.<br />I checked the impeller, it 'seems' OK. Flexible, no tears or missing vanes. The outlet is above the inlet, but this seems to be the way it goes together as the drive and gear shafts are in the correct places.<br />I have tried attaching a cordless drill to the drive shaft to turn it .. only 600 rpm. but still no pumping action.<br />Any suggestions?

 

[one more cast]

Re: 1981 Evinrude 7.5 hp no water prob impeller trouble

welcome tbarker, <br /> You have the hard part done,why not replace the impeller? You can get one at your local NAPA auto parts store for about $15. Also use a service manual to make sure your installing it corectly.<br />+++++++++++++++++++++++++++++++++++++++++++++++++<br />OMC

 

[jim dozier]

Re: 1981 Evinrude 7.5 hp no water prob impeller trouble

You say there is no thermostat. Does that mean it is not installed (missing) or that this particular model does not have one. I agree the impeller should be replaced. From what I have read sometimes looks can be deceptive, anyway they are relatively cheap. Also look at the impeller housing, any nicks, holes, or corrosion, will decrease its pumping ability. When you have the water pump apart connect the copper exit tube to a hose and see if water circulates through the engine and out the exhaust (this will only work it there is no thermostat, also make sure the engine is upright so water does go into cylinders). If it turns out to have a thermostat after all check to see that it is opening by boiling it on a stove and checking the temp with a cooking thermometer. Also while its out you can back flush the coolant passages with a garden hose. Clean out the "**** hole" and make sure it is not clogged.

 

[tbarker]

Re: 1981 Evinrude 7.5 hp no water prob impeller trouble

Thanks for the advice.. I went to a local evinrude dealer with the bottom part in hand and showed it to him ...<br /><br />It seems that there was a plate which fits directly under the impeller missing! Any wonder the thing didn't work .. sheesh.<br />Anyway, $75 later, (that's Australian dollars - probably about US$35) I have a new impeller, cup, plate and gaskets all fitted.<br /><br />I bolt it all back on the leg, fire up the motor and Viola! Water coming out of the correct holes.. <br /><br />Now I can go sailing ...LOL...