Agree with the previous posts..., I would run it at close to maximum recommend slack. I would doubt if it’s jumping the drive sprocket unless it’s severely worn. When I raced 2-stroke karts, chain alignment and slack were of critical importance. Aluminum split gears and used D.I.D. Gold Chains. Would crank over 15,000 rpms on the straights. I would set my slack and then having the kart level on a stand, rotate the axle forward (how it would normally be driving) and adjust the axle gear so the teeth were ideally perfectly centered to the chain. Not touching the insides of the links if possible, or as close to that as possible. Look for wearing on the sides and leading edge of the teeth. If you see any, replace the gear and chain at the same time.