[Collin]

I am having a terrible problem with hanging idle, so we are going to do the jetting and the ap mod just as ~ and all others at CRFs has recommended. However, what is the rivet grind and does it pertain to the 150R?

[Asmith]

The rivet grind pertains to the AP diaphragm and the rivet in the center of it. Grinding the rivet changes it's length and the way gas is pushed into the AP circuit.

That is usually the last thing done while chasing an off idle bog.

The hanging idle plagueing your bike is most likely solved with a larger pilot, overall jetting revamp and the fuel screw adjustment.