If your slider clutch doesn't want to disengage at the end of a run, it could be overheated. This causes the clutch plates to stick and not release.
Not having enough weight on the arms or coil binding of the stall springs can cause it to overheat during a run.
Putting an excessive amount of heat into the clutch during the burnout can cause your bike to creep, pull through the lights, or fail to disengage at the end of the track. You can help alleviate this problem by doing your burnout at least 2000 RPM above the stall speed to keep the clutch from slipping.