1982 Evinrude 4 hp E4WCNR overheating

dockrat100 · Mar 21, 2012

I got this motor running well, but now it is running hot. It has a new water pump housing, impeller, and I feel some water flowing out of the exhaust holes on the leg. I did drop the lower unit to see if the water tube is in location properly, and it is.

It is running hot enough to boil water off the head.

What else is there to check? How hard should the water pressure be coming out of the holes on the leg? I am thinking a partial obstruction somewhere, but can't picture where to look.

nwcove · Mar 21, 2012

Re: 1982 Evinrude 4 hp E4WCNR overheating

is the water tube grommet in good shape?

dockrat100 · Mar 21, 2012

Re: 1982 Evinrude 4 hp E4WCNR overheating

nwcove said:
is the water tube grommet in good shape?

The grommet on the water pump housing into which the water tube goes, when installing the lower unit? It is new, and in good shape.

nwcove · Mar 21, 2012

Re: 1982 Evinrude 4 hp E4WCNR overheating

are the impeller plate, housing, and gaskets in good shape? impeller vanes oriented correctly?

Will Bark · Mar 21, 2012

Re: 1982 Evinrude 4 hp E4WCNR overheating

Is the leg deep enough in the water?

dockrat100 · Mar 22, 2012

Re: 1982 Evinrude 4 hp E4WCNR overheating

Sorry it took a while to respond, but I wanted to check a few things.

The impeller plate and impeller are all new. Impeller vanes were correctly oriented.

The leg is plenty deep in the water, all the gaskets appear to be in good condition.

I did pull the head gasket and found a fair amount of what appears to be lime scale inside the water jacket. Would this act as an insulator, preventing the cooling water from absorbing the heat? Soak in limeaway in order?

dockrat100 · Mar 22, 2012

Re: 1982 Evinrude 4 hp E4WCNR overheating

It appears that the water tube grommet on this motor is a gasket, on the engine end of the water tube.

nwcove · Mar 22, 2012

Re: 1982 Evinrude 4 hp E4WCNR overheating

i think there should be a rubber grommet on the pump end of the water tube, but did the tube pull out of the motor when you dropped the lu? ( not framiliar with your model, but have never seen one that doesnt have the grommet on the pump end.) post pics of the set up!

dockrat100 · Mar 22, 2012

Re: 1982 Evinrude 4 hp E4WCNR overheating

nwcove said:
i think there should be a rubber grommet on the pump end of the water tube, but did the tube pull out of the motor when you dropped the lu? ( not framiliar with your model, but have never seen one that doesnt have the grommet on the pump end.) post pics of the set up!

This has a grommet on the pump end, and it is in fine shape. The parts manual lists a water tube grommet for the powerhead end, that is in fact a gasket. I just stripped the motor apart and cleaned all the coolant passages with a wire, and scrubbed the lime scale off the water jacket walls. I will post results when I can get it started. (Now I lost spark on the bottom cylinder.):facepalm:

nwcove · Mar 23, 2012

Re: 1982 Evinrude 4 hp E4WCNR overheating

you should get yourself a new head gasket, and check the head for "trueness" while its apart. ( a leaky headgasket can cause a motor to run quite hot also)

dockrat100 · Apr 6, 2012

Re: 1982 Evinrude 4 hp E4WCNR overheating

I finally got time to put this motor back together, and it seems to be running fine now. I think the lime/ hard water scale inside the water jacket may have been plugging a water passage, but it is good now.
Thanks, everyone.

1982 Evinrude 4 hp E4WCNR overheating

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