I've replaced waterpump impeller, I've blew air and water through passages and their clear but but still getting no water from tell tale,took thermostat out and boiled and opened and closes. I'm at a complete loss now. Any help would greatly be appreciated 2016 mercury 15hp carburetor 4 stroke
do you have a fresh water flushing port on this engine ? my 2016 larger merc does. I know that some have had issues with these not being tight enough or leaking, causing a drop in pressure enough to make the tell tale suffer. Other similar issues on larger engines like mine can be caused by a blocked strainer on the water system. This is on top of the engine on mine at least. You may not have such a thing though.
Failing the above, I might check that the seal on the pick up tube running up the mid section from the impeller, is in place and sealing.
All of the above is only relevant if you have the correct and suitable means of supplying water to the engine whilst running. some muffs don't seal on smaller engines and sitting in a bucket just won't do either, on occasion. Have you tried it in deep water that's definitely of a level considerably submerging the whole lower unit ?
