Troubleshooting malfunctioning H bridge
1G are smaller NPN transistors. Generic type:2N2222
Y5 are larger, heavier current NPN transistors to take motor current. MJE181 current rating of 3A might be adequate, a lower voltage rating is OK. 
Y6 are large heavier current PNP transistors to take motor current. MJE171 current rating of 3A might be adequate, a lower voltage rating is OK.
With only 3V supply, a low saturation voltage would be beneficial.
You'll have to determine transistor base pinout.

Input 1, input 2 are logic compatible. Caution: a logic "high" on both will turn on all transistors, and kill them (or your battery). Only allow one of these inputs to go high.
When both are low, the motor should be off.