1971 50 HP Evinrude No telltale run on muffs

[w2much]

Just tried my motor Model #50173S. Ran it on muffs instead of a barrell. It ran fine and cool, never hot or warm to the touch. No water ever showed out of the exhaust pisser. However blackish water did show through the prop exhaust hub. How can I tell if the water pump is pumping when running out of the water but with the muffs attached?

 

[MCM]

Re: 1971 50 HP Evinrude No telltale run on muffs

It should get fairly warm at least if not the t'stat may be stuck open or not there at all.<br /><br />Have you ever replaced the w/pump and t'stat? if not and you don't know when it was last done it might be good time to do so.

 

[w2much]

Re: 1971 50 HP Evinrude No telltale run on muffs

Just got the the motor this AM, brought it home and started it up. I was told it was recently serviced, what I don't know. I was hoping the water pump to be good . Is there a way of telling when running on muffs? <br /><br /><br /><br /><br /> MCM, by the way that was a great refferal on the electric shift question. Thanks Again.

 

[MCM]

Re: 1971 50 HP Evinrude No telltale run on muffs

The only way of knowing for sure since you just got it is to do them yourself then you'll know. Beyond that once the t'stat opens up (usually around 140-150 deg.) there should be a spray or slight stream coming out of the exhaust ports, I think at higher rpm's its diverted directly out the exhaust at the hub.<br /><br />The fact that your motor is not getting very warm would seem to indicate at least the water pump is working.

 

[surlyjoe]

Re: 1971 50 HP Evinrude No telltale run on muffs

if theres no water coming out the upper exhaust port, then the thermostat is stuck.<br /><br />like MCM said, at least look at the impeller, and since your in there ya gotta replace it. lack of water pressure kills more outboards than anything else.

 

[OBJ]

Re: 1971 50 HP Evinrude No telltale run on muffs

When running on muffs, there maybe no water at all coming from the relief ports because there is no water around the midsection to cause any backpressure which would cause the misting out the exhaust ports. The blackish stuff coming out is probably unburned fuel and oil. With no backpressure, the engine runs really easy. With the engine running cold, good combustion is not happening and some of the fuel/oil mix ends up out the exhaust.<br /><br />As MCM posted, the engine should come up to temp on the muffs. As he posted, the t-stat is either stuck open or not there. I agree with the other guys, if you don't know when the impeller was changed out last, do it.....and replace the t-stat also. A cold running engine does not run efficently and builds up carbon quicker than an engine running at normal temp.

 

[w2much]

Re: 1971 50 HP Evinrude No telltale run on muffs

Had to work on it again today. Decidied to keep it quite and let the neighbors enjoy their Sunday. Ran it in a barrel of water. Telltale was there good and strong from the exhaust port. So I guess the answer is as you all stated. The water was pumping. Needed back pressure to exit the exhaust port.<br /><br /><br /><br /><br />Thank you all for your input. Yes I will still put in a new impeller and tstat. Thanks Again.