Posted for "Chuck Jensen" <cjensen@dts9000.com>:

            Jeff,
 
            Run up on the tank before takeoff is probably not enough.
 Depending on the fuel system volume and exchange rate through the lines,
 filter and pump, you may not actually get into the new tank, or not into
 it enough to discover degraded fuel before take off.  Earlier posting of
 start up, taxi, run up, take off and cruise on the first tank is solid
 advice.
 
            Chuck