1994 Mercury 150 hp EFI stopped peeing water from the tell tale. Did not overheat. Dropped lower unit and replaced impeller (which was original - low hours on motor). Gaskets and plate also replaced. Old impeller looked ok (no pieces missing) Blew air thru cooling system from water tube and air came out tell tale hole. Also put air into lower unit pick up using hose attachment over water intake and air came out at inlet to water pump (with pump housing disassembled. Put all back together and still no water coming out tell tale or any where else it shouldn't. Disassembled again and rechecked everything, reassembled and still no water.
Blew air into tell tale hole and air came out water tube at pump (with lower unit removed). Also blew air thru lower unit water intake and it is clear to inlet to pump. Never ran in sand or silt.
Hi there i have a 70 merc and it did the same thing and i finaly changed the impeller plate, gaskets and the upper housing because it was a little melted and that finaly fixed the problem. apperantly if the metal cup has any wear they will not pump water so check that plate and cup very closely. hope it helps.
Mercury outboard not pumping water
did u try to force air back thru pee-hole?
Linear Mode
