my 1992 40elrq is overheating

[lahainaboy]

hello i am new here so i dont know all the rules, sorry.
i have a yamaha 40elrq 1992 and it just started overheating at idle.
i cleaned the tell tale tube and i have good flow but it gets very warm before alarm goes off.
i pulled the thermostate and checked it for correct opening temp 135-145 it seems ok.
all was clean inside as it is only used in freshwater.
i re assembled without thermostat to see if situation would be the same and it was identicle problem.
there is good stream till alarm goes off and then it deminishes.
is there a poppit valve or a pressure relief valve that needs servicing?
i cannot seem to locate it or its position.
in all this time the impeller has never been replaced and i will begin there after i figure out about the pressure control valve.
thanks in advance.

[99yam40]

replace the water pump, get the kit not just the impeller, inspect the housing to see if it needs replacing also, no PRV on the 40.
Yamaha recommends replacing every few years as preventative maintenance and yours is way overdue,
It is like running your auto without changing oil, antifreeze, belts, etc. until you break down on the road somewhere and it is too late for the cheap preventative stuff