115 hp Suzuki DT outboard motor Problem

I have a 1991 115 hp Suzuki DT outboard motor . At start up ,it takes 15 to 20 second for the water comes out of the pee hole.Once the water comes out it is strong at idle even at half throttle.But trying to get up on plan I'm fine for about 2 minute then i see the water low flow light come on and and the pee stream seems to fall off .So i back off the throttle and the light stays on but no alarm.But after a few seconds the stream picks back up .And the low flow light goes out .Some times there will be a white puff of smoke coming out of the back of the motor assuming it steam from the motor.Soon as the water comes out of the pee hole the everything is fine .I can run all day at half throttle .

Could the pressure valve or the poppett valve cause this problem ? Where are the valves located ?

I have replaced the water pump impeller and the rubber gasket under the water impeller where the water tube and exhaust are .Thinking i was sucking air or exhaust .

Please help !

Beach bum