I have a 1989 Merc 115 outboard, 4 cyl. I just bought the boat and figured that no tell-tale was the typical worn out impeller, so did not think much about the purchase, as this is a relatively easy fix. I have checked the tell-tale line several times and it is not plugged. I replaced the water pump, and still cannot get water out the tell-tale hole. I checked the thermostat and it was clean and opened when put it in hot water on the stove, so I reinstalled. I now have the lower unit back off and have tried to run water thru the motor via a garden hose with a spray nozzle that sealed on the water tube nicely, with the engine off, and I still cannot get any water out the hole; is this a way to see if some passages are plugged, or do I need the lower unit assembled and the motor running to tell? If this method should work, what would be the next step to find the restriction? How much disassembly might this need? Thanks in advance for any help!!