2008 Precedent dieseling

[Fairtax4me]

An ignition timing issue could cause it to run hot. The only way that would happen is if the flywheel got loose on the crankshaft and spun off of the keyway notch that lines it up at the proper angle, which is not unheard of, but is unlikely.

With the fan cover removed, make sure the nut in the middle of the flywheel is tight. If it is loose or looks worn the flywheel may have come loose.

The only other thing I can think of is an air leak between the carb and the head, or the carb main jet is partly clogged and making it run extra lean. A clogged jet or main pilot tube seems more likely.
Remove the carb, remove the bowl, and remove the main jet. Then use a screwdriver to press down on the brass tube in the center of the carb throat and the pilot tube should drop out. Make sure all the holes in the pilot tube, and the hole in the main jet are totally clear.