Home › Forum › Ask A Member › 1969 Evinrude 6hp cylinder head cooling problem
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fleetwin.
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July 18, 2024 at 9:51 pm #289258
Hello, my 1969 Evinrude 6hp fisherman will start up and run pretty well but everything is cool to the touch except the head. I know the impeller is good I have tested it, I took the head off in the past to clean the passages and they are clean, but it still gets hot. I reused the head gasket and put gasket sealer on it, is possible I put too much gasket sealer on it, and it is blocking the wholes for water to pass through and cool the head? The gasket sealer I used was more liquidly than the ones I normally use so I am thinking that is what it is, and I need a new head gasket, I am looking to get others’ opinions if that maybe the problem or not. I am getting good water flow out of the water outlet, but I don’t think that means anything, because the water circulates around the cylinder wall and can go through the cylinder head, but it doesn’t have to exit the motor, (if I remember correctly from when I had the head off last, not 100% on that).
July 19, 2024 at 8:01 am #289261the water circulates around the cylinder wall and can go through the cylinder head, but it doesn’t have to exit the motor,
yes it must exit the motor othewhise it would heat up !
pull your cyl head and inspect closely. use a new head gasket esprcially if cyl walls look normal heat wise
check inbound and outbound water flow ports into the ph.
btw if you worked on the base gasket make certain you used the proper one….patterns differ
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July 19, 2024 at 8:29 am #289263Hmmm. Good water flow out of the relief hole but the head gets hot?? Is the exhaust manifold somewhat cool? It almost seems like the thermostat is stuck closed, did you check it? Water seems to be getting into and out of the powerhead OK, so I would say that either the thermostat is stuck closed, or the water passage through the head is blocked/jammed with crud. Is this a fresh or salt water motor? How about temporarily removing the thermostat, reinstalling the cap and trying it out….
In any event, the head gasket should be replaced, have a super close look at those crazy passages in the head before reinstalling, post pictures also. I don’t want you installing a new head gasket only to have the same issue.
How about the thermostat gasket? Did you replace it? Keep in mind it could be that the little bypass passage in the thermostat cap could be plugged up as well…
July 19, 2024 at 10:05 am #289268I have removed the thermostat from the housing when I had the engine disassembled to put a piston ring in and made a gasket for that. The exhaust housing is cool to the touch even when the cylinder head is hot to the point you can’t really touch it.
I will take the head off later this afternoon and try to upload some pictures.
July 19, 2024 at 10:18 am #289270When I touch the head, I am really mainly touching the water passage in the middle of the head and thermostat housing. When I shut it down, I touch the areas around the water passages on the head and they are still real hot, which make some sense, but it shouldn’t be as hot as it is getting.
July 20, 2024 at 8:04 am #289285tried hot vinegar flush to loosen up calcium-mineral deposits ?
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July 20, 2024 at 9:13 pm #289302Perhaps you home made gasket isn’t correct. I would order the correct gasket before going much further. 311145 from OMC/BRP
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