Hello, my Merc 115 (1978) appears to have a problem. It is running perfectly, but the tell-tale water squirt has reduced to a mere trickle......can someone please give me a diagnosis and step-by-step idea of how to fix this problem. Thanks from AUSTRALIA!!ERIN
hi friend from australia....wish i was there get a lot more boating in ha ha! well it could actually be three things your thermostats are not opening all the way and if your running in salt water this could be the problem or your impellar, my advice would be and if your pretty good with tools go and buy the service manual for your motor Clymer publishes one that is very good and you can order it through the net and recive it in about two days , this is a very good book with lots of illustrations,you will not only save money doing the job yourself but you will get to know your motor inside and out.and hey your friends will be impressed too ha ha! good luck!
Your water pump could have picked up some trash also. That could be inhibiting your waterflow. Air pressure could free it up, but definately check, and change water pump if it hasn't been changed in a year or so. You can do this yourself, especially with a manual. Good Luck, tell us what you find
Before I did anything ,I would check to see if the tell-tail spout is plugged or even cracked allowing water flow to bypass the nozzle. They like to crack on the inside where you can't see it(thus reducing flow)
I'd try heavy mono line up the hole before anything else as I have had mine clog up twice, once was a wasp that had gone up to make a home. If motor is over heating then it's probably time to put in a new Water pump impeller.
1978 115HP Mercury poor water tell-tale??
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