Primary springs control engagement and shift rate. Our springs are made from high tensile wire and will hold rate better than cheap springs. The first force number listed controls what RPM your clutch engages and the second number controls how fast the clutch upshifts. 
 
Force Lbs. @ 2.50″ – 1.19″ 140-330 Green
 
SKU: 210135-001
Product Type: Primary Spring