After installing a new water pump impeller in a DT-6 Suzuki I noticed week or no water flow at idle until reved up 1/4 of more with the water level above the water pump. When you fill the barrel water level above the shift shaft inspection hole it will pump week at idle and real good above that. Is this normal or a sign that there is a leak in the pipe gromet or someting else. <br /><br />Thanks, Pat