Re: First break down....
What do you mean by "gave out"? What actually failed? The plastic part the cable wraps around is called the thimble. That's what usually breaks. The reason is too much force being applied to the twisting action and the cable being pulled very tight against the plastic. You can adjust the cable length and tension to keep that from happening again. Most any motorized bicycle twist grip throttle you find will be of about the same quality so take it easy with your replacement.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"