My small yamaha outboard appears to be over heating. The last time I ran it it shut off in me and wouldn't restart and when I felt the head it felt very hot. So I changed the water pump housing and impeller/pump kit/spark plugs and thermostat. Running the outboard on the stand after all of these changes, the head is still hot to the touch and the weep hole will start pretty strong and then a few minutes later the water is dribbling out. The water jacket does remain cool but I don't really know how cool the head should be to the touch or how much water should be coming out of the hole. The head is hot but I can still put my hand on it without pulling my hand away. I don't know a lot I out outboards so any help would be appreciated. Thanks!
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- Thread starter dgram36
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Water out of the hole is good. Steam is not. If you can put your hand on the head for about 3 or 4 seconds, your motor is cooling correctly. The head will be hot, but not burning.
As to the strength of the stream, is it increasing with an increase in the engine speed? At idle, the stream should be steady, but it will certainly not be as strong as it is a full power. If you are just seeing a small dribble or drips coming out, then you've probably got a blockage or restriction somewhere.
Good luck!
As to the strength of the stream, is it increasing with an increase in the engine speed? At idle, the stream should be steady, but it will certainly not be as strong as it is a full power. If you are just seeing a small dribble or drips coming out, then you've probably got a blockage or restriction somewhere.
Good luck!
Thanks for your reply. Perhaps I am over reacting and the engine is cooling properly. I can put my hand on the head for quite some time and it is hot but not burning. There is a steady stream coming out the hole but it seems to taper off quite a bit as time goes on. If I rev the engine the stream does increase. When I changed the water pump I was able to blow down the tube pretty freely so I feel as though there isn't a blockage. I guess I will just run it this weekend and see how she does.
Sometimes on the Yamaha's I'll pull the thermostat out and then start the motor, with the cover off. If there is any blockage, it comes right out. The pee stream should be mostly steady on most any Yamaha I've had to work with.
Mercury/Mariner can be a different story......
Mercury/Mariner can be a different story......
