My BX2200 will start but kills when I let go of key. If I hold it in start it runs. Recently backed into a tree and had to replace nipple on fuel tank.
Check the injection pump shutoff solenoid, perhaps connector is loose. Three wires (usually)
One wire energizes during crank, pulling solenoid, next wire goes on with key and remains on to hold solenoid while engine is running.
Remaining wire should be ground.