Place corn in a large pot, add sugar and fill with water. Allow to soak for at least 1 hour, up to 4 hours.
Preheat grill to high 15 minutes before you are ready to use it. In a small bowl, melt butter (microwave for 15-30 seconds). Add salt and cayenne pepper. Set aside.
Remove corn from water and place on a tray. Using a basting brush paint butter mixture on corn.
Place corn on grill, arrange so they are not touching.
Allow to grill for 3-5 minutes and then check for grill marks. Once corn is golden brown turn and place uncooked rows of kernels on grill. Using a grill basting brush, carefully apply a light coating of butter to the top of the corn. (BE CAREFUL: Applying too much butter can cause flair ups!!!) Repeat this until the corn is completely grilled.
Remove from grill and serve.
Notes
Corn reheats well in microwave.To reheat: cover with a paper towel or plate and microwave in 30 second increments until corn is warm to the touch.