Hello Danny ... Unfortunately, I don't have a solution for you other then getting a custom made cable. I've never tried that swap in person, but most likely it won't work, as the DT100 has a much smaller carburetor on it then your RT180.

If somehow it's even long enough to reach the carb at full turn (problem #1) . . . and if you manage to get it attached (problem #2) . . . the inner cable probably won't have enough slack to let the throttle slide drop down. (problem #3)

Best of luck anyhow, and thanks for asking.

Dave/Enduronut