There is a "detent" that is at the lowest throttle setting. You should have to push the lever past the detent to shut off the fuel. If it stops running at the lowest throttle position then it needs to be adjusted to the correct rpm.
Hi Team,
most times the detent can be hard enough to pass-by from the Low Idle to the Stop Position that the linkage seems to deflect if you push the Gov. lever forwards hard and so the engine does not shutoff.
You often need to slightly Rev. the engine and then slam the lever forwards to have linkage momentum by-pass the detent--I recall as a light weight greenhorn Apprentice at The Dealer back in the day having trouble shutting off engines as I simply slid in the seat--slight rev and bang the lever forwards did the trick--especially D7E and D8H etc.
Similar can happen that it takes a fair effort to get the Gov. lever to open the Gov. for a start--push forwards a bit and heave back past the detent.
Cheers,
Eddie B.