Regarding my Post# 31306 above.
The spring I'm referring to is NOT the retrofit one from the G4 that centers the forward/back motion of the handle slider.
The one I'm asking about is a strong coil spring inside the handle pivot hinge mount. The coil has pins at each end that fit into corresponding holes on the end bushings, engineered to keep the handle more or less upright when released. the bushing on the left is meant to rotate with the handle while the one on the right should be stationary. The bushing on the right has a flat sided keyway that locks with the axle pin so the handle is free to rotate forward and back but return to upright when released.
My bushing got cracked open and distorted when the handle clamp rivits popped open. So the coil spring no longer has any effect since the one end no longer locks to the axle flat keyway.
Wish there was a walk-in KIRBY Repair Depot close by...I'll ask my local guy if he can order this part for me.