Motor Discharges Boost Converter Too Quickly
If you have the current but not the voltage to drive your dc motor you might be disappointed. You might have the ability (in your battery) to supply 1 amp at 3 volts but, to power a 1 amp motor with 9 volts means your battery will need to supply maybe 3.5 amps into the boost regulator.

Power in equals power out plus losses and to obtain 9 volts at 1 amp requires a power in of 9 watts plus about 15% extra for the boost converter losses. That takes the input current up to about the 3.5 amp level. Can your battery sustain this level I wonder?