Too much slip

[jamesban]

my setup is a 40 x 82 mm 2000kv motor, 4 cell A123 batteries and 14T pinion in a Muggy. I lightly scuffed the slipper pads. I made sure none of it got anywhere on the slipper when I lightly greased the threads on the adjustment ring. I have it tightened all the way down and it still slips so much the truck will not barely move. Is something wrong ? or do I just need another spring maybe in this heavy truck with a 2000kv motor?

http://www.youtube.com/watch?v=VnQ06skycxU