no water flow 63 evinrude 40hp big twin

[mfsekk]

need assistance. recently bought motor. not pumping water, removed lower unit and impeller looked ok , but i changed it. checked that water tubes installed correctly, blew air from water intake though impeller housing, seems clear. what am i missing, or further troubleshooting tips?

[Bob Wight]

Check the water tube up through the mid section to the powerhead. Water tube or engine water jackets could be stopped up. Also check the grommet where the water tube is connected to the water tube. If the grommet is missing, damaged or folded over into the pump housing it will prevent or restrict water flow.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

[fleetwin]

First, how are you test running the engine? In a bucket, on a flushette, on the boat in the water? Next, what makes you think it is not pumping water? Did it pump before you pulled it apart?
The engine has to be sunk pretty deep in a bucket before it will pump properly. Keep in mind that you won’t see much water flow from the upper exhaust relief even though the engine is pumping properly. You will see a little more spray when the thermostat opens up. Is the engine actually overheating? Keep in mind that there is a plastic check valve and spring in the thermostat housing that must be in place and operating properly, or the cooling water will just “short circuit’ back to the pump without circulating through the block.
The engine is new to you, does it appear to have been over heated (discolored/blistered paint or melted wiring)? I don’t mean to throw all these questions at you, I just don’t want you to go crazy trying to fix something that might not be broken. You have had the gearcase off, so you know there are two water tubes, and you indicate the water tubes were correctly seated in the impeller housing. You mentioned the impeller “looked OK”, did you replace it with an OEM or aftermarket impeller? How did the inside of the impeller housing look? A worn/grooved/corroded impeller housing will keep the engine from pumping properly even with a new impeller. Again, this is a somewhat complicated cooling system, I just don’t want you going crazy trying to fix something that isn’t broken….D

[frankr]

Sorry, but gotta ask this: Where are you running it? Bucket, barrel, on the boat on the lake, where? We get a lot of inquiries about the 40hp not pumping and it often is just a matter of not enough water to the pump.

If you are positive you have it deep enough in the water, check the thermostat. People love to take them out and throw them away—along with the plastic thermostat housing and check valve. That’s just the wrong thing to do.

Water discharge normally varies according to thermostat state. But there should always be at least some spray out the exh relief.

It is hard to plug up the cooling system on those motors, but I suppose it is possible. But unlikely.

[frankr]

fleetwin and I think alike, at the same time, I see.

[fleetwin]

I learned from the best…..

[mfsekk]

Thanks, I checked the tubes and grommets, seem to be fine, will check thermostat .

[mfsekk]

I had it in garbage pail up to the top of lower unit. Grommets and tubes look good, replaced impeller with model number from parts catalog. Existing impeller looked good and housing appeared in good shape, don,t think the problem is there.Had this problem when I first got it and before I removed the lower housing. Heads were getting hot , so I shut it down each time, but not too excessive to peel paint.so I believe im not getting circulation, I will check thermostat. Should I temporarily remove it and then try?

[mfsekk]

How high should water level be, I had it too top of lower unit, should I try with a muffler and forcing water in? Can I remove thermostat temporarily and try it? Engine heads get hot

[frankr]

Get it down in the water.

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