The throttle shaft seal is one of the common leaks I mentioned above (using your term "accelerator"). Almost always a new o-ring seal fixes it. Have never seen where it needed a new bushing, although is is possible if the throttle shaft has excessive play (slop). For it to need a new throttle shaft indicates that it must have been leaking a very long time.
If it's a good shop and technician, the reseal can be done with the IP still in place.
Wouldn't hurt the remind the tech to matchmark the throttle lever to the throttle shaft before he removes the lever, and:
PROTECT THE HEATER HOSES RUNNING UNDERNEATH THE IP FROM DRIPPING FUEL.
Here is a photo of the throttle shaft and its o-ring seal: (Thanks to
Tom Bryant, Wiscasset, Maine
https://thosbryant.wordpress.com/)
from
https://thosbryant.wordpress.com/201...-pump-re-seal/
About 2/3 down, where he says: "Install a new o-ring on the “throttle” shaft:"
Here is another photo of it, getting ready to be installed into the top cover:
Fair warning: Often, the first IP leak to emerge is an early signal that others are on their way...