NEED futaba ESC HELP
 

Hi I'm new to the forum and I hope someone can help -I have a futaba mc112b esc-It works fine in forward but when you try reverse it doesnt do anything for 1-2 seconds then it goes in full speed reverse-its not proportional in reverse. Another strange thing is the check light on the esc lights up in forward in proportion to the amount of throttle you are giving it-in reverse it doesn't light up at all. This is in an old blackfoot that I got with no transmitter-I am using a new futaba magnum sport to run it-it does the same thing with the old receiver and the new one that came with the transmitter. Thanks in advance for any help