| Green Spring: usually used in 7.90 motor. Rpm engagement range is about 4600 to 5000 depending on ramps and weights. Purple Spring: usually used in an 8.90 or 7.90 motor. Rpm engage range is about 4400 to 4600 depending on ramps and weights. Orange Spring: usually used on 11.90 motor and slower. Rpm engagement range is about 3800 to 4000 depending on ramps and weights. | 