I have a 2000, 150 Merc. I've never changed the impeller.
My question.
When I run the motor on the cups, it takes approx. two minutes before the water comes out the pee hole. Water is coming out the exhaust immediatley.
Any ideas, is this normal
Mine does the same thing, i believe it wont come out the pee hole tell the motor reaches a certin temp.
Once it comes out the peehole then the water is now cooling your motor.
PS Change your impeller, preventive maintance is the key to a long motor life!!!!!!