10518 spraying fuel from gas cap

I have a 10518 that I bought used 20+ years ago die on me last fall, it also started leaking gas onto the deck at the same time. Took it to a repair shop this spring and when I got it back, it still leaked. Took it back again. Leak was fixed (new shut off valve), but now it sprayed gas out the cap. Took it back again and they said ports were plugged (weird-didn't spray before). Paid them $30+ to clean, still sprays! Won't go back there again. Any thoughts on cause and cure?
Thanks