[jclark003]

I believe Tiara usually bottoms the generator pickup at 25% tank capacity. Depending on sea state the gen could pull air at a higher fuel level. 1/2 tank however sounds way too high. Possible you have a cracked pickup tube or more likely have a small air leak that manifests itself when fuel level drops and vacuum increases. Only other thing I can think of is a sender reading too high (just went through this with a friends boat). If you filled up both tanks however that pretty much takes it off the table.