Never personally experienced or noticed it in the FiST. Stock drivetrain and exhaust. It's pretty quiet so there's no point in running a wwaayy-higher-than-necessary RPM unless there are severe traction issues, such as going down a steep slippery hill.
Re
cause, sounds like she has the RPMs way higher than is necessary
while feathering the throttle.
That is literally the only condition that causes it on the motorcycle and I only did that, either when someone was needlessly yoyo-ing their speed resulting with
constant up/up/down/down shifting or if a particular PD was skulking for (certain kinds of) cars/people going 6.205789 MPH over posted.
Best of luck, pops are also caused my fuel getting into the exhaust are they not?
Yes it's from a buildup of unburned fuel, detonating in a hot exhaust. As long as it's not a constant or extreme thing, potentially overheating the catalytic converter, it doesn't hurt anything.
I think this can point to an evap system issue as well.
Evap recycles fuel tank vapor emissions into the air intake. I suppose it's possible but a solenoid valve malfunction theoretically should set emissions code(s).