I have a 1998 roadking and the turn signals stoped turning off automaticly, any advice.

 

 

Try adding more blinker fluid………………..J/K…………..My guess is the box that has the float or whatever is use to sense that the bike turned is bad.

 

is the speedometer still working correctly?
The blinker cancellation is controlled by the speedo sensor and the transmission.
Basically, when the sensor detects that the bike is over 25 - 30 mph and has shifted into another gear then the turn signal auto cancels.
You can remove the sensor and clean it with a bit of wd40 or mineral spirits.

Look at the area between the back of the engine and the front of the starter...this is basically the area directly behind the Y where the pipes intersect.
at the top of the tranny box there is a small sensor with one wire. Remove the sensor by removing the allen screw. Just pull the sensor out, clean it reall good and replace. You will not loose fluid and there is no need to replace any gasket.
That should do the trick.