Hi - just happened to me on my BX 23 two days ago. I didn't know at the time where the solenoid was (its very well hidden), so had to resort to siphoning the fuel from the tank and pinching the fuel lines with vice grips. Took me two hours to get it to stop. On the BX 23, the solenoid is on the side of the engine hidden by the air filter. I found it by feeling around (with the engine cold). I didn't feel a trip lever, however, it is a few years older than yours. After I get it back together, (and IF I can get it started), I need to test to see if I can trip it manually. Now I need to reprime the fuel system - apparently, they don't like being shutdown by fuel starvation. I've read somewhere that some injectors may be damaged as a result. I do know the tractor makes quite a racket (it sounded very painful) when you shut it down the way I did, so hopefully I can manually trip the solenoid if I need to in the future.