Adjusting the centax clutch. Your endplay or gap is at minimum .06. Preloading the spring to a 9-10mm to the end of crankshaft, is only a starting point. Adjust the collar CCW for earlier engagement, it wont take much. Adjust by using allen wrench through hole of the pinion cluster. One thing about Centax it take a lot of maintenance, scotch brite the flywheel and clutch material cuz it glazes with it engages so late.. preload at 9-10mm it engages almost 1/4 - 1/3 throttle. You'll find the optimum that suit you. Have fun!!!