There is a guy a few houses s down who uses a fairly late model power torque (late 1990s -2000s at a guess) and he always has it revving abit higher than it should at full throttle, but not at scary levels like you describe, just a higher note (might advise him to back it off a little!). His hasn't popped so far. It's usually a sign of an air leak somewhere, maybe the o ring where the carb attaches.
Sounds like you don't get much throttle control either. I would advise not to let the motor starve of fuel until you get to the bottom of the problem, or fix the kill wires/ install a spring loaded switch to stop for machine from becoming an air raid siren, or worse, a starters pistol.
