The fuel shutoff on our Mitsubishi marine diesel in the cape islander was held by a spring until the valve was closed.
One day the spring broke and killed the fuel to the engine. My co worker jerry rigged it with an elastic band. That worked for a while, until it got too hot and broke. This killed the engine and we ended up on the rocks with a receding tide. It was a long day doing fibreglass repair until the tide could lift her again.
During one patch, my co worker decided we were working too slow and added a bunch of hardener to the resin and as it cured it caught fire. We got it out quick enough, but scorched the white paint. Between the list, the patches and the burn marks, the poor old boat looked like it had been through the battle of Jutland.