Micro 4k throttle stop screw

The 4K has what is called an 'Throttle stop screw' to adjust it the generator has to be running with no load.

Adjustment is as follows:

The following is from Micro 4K spec B manual (pg 8-13) same for other 4K models.

A throttle stop screw is provided for adjusting the
“closed” position of the throttle plate to obtain proper governor response when loads are being disconnected. (See Governor Adjustments on Page 8-9)

To adjust the throttle stop screw:

1. Connect a frequency meter (Kill O Watt) and start and run
the genset until it has warmed up to normal operating temperature.

2. Disconnect all loads. Pull the governor linkage
toward the front of the genset so that the tang
on the throttle lever bears against the throttle
stop screw. Adjust the stop screw to obtain a
frequency of 54 to 56 Hz on 60 Hz gensets (44
to 46 Hz on 50 Hz gensets).

For manuals:

https://www.smokstak.com/forum/forums/onan-generators.1/