Tiger that ebay number for the (speed booster kit) is 350187954623 It is 34,99 buy it now and 6.99 shipping. I emailed the guy and he said allways wait until full speed before you pull the switch and it would not hurt the motor. My cart had it all ready, but i was looking for something else and found it. . Check before buying it , I dont want to be the cause of you frying your motor. ...