How short has it busted off???
If its the kind with the white bit/barb on the end, i have just put the hose on whats left of the black and it is usually long enough.
Another option could be, depending on where you live, a dead victa is only about $20 away. Chances are if you clean the carb out and put it back on said dead mower it will go like a beauty and you will not want to wreck it.
Bob.
