Duncantoms

Hi I was given a 90s Le Mans set and am trying to get it running. The power base has four pins, two for each slot lane. None of the straights have four pin holes, just two for one lane, so I'm wondering how to connect the power base properly. Am I missing a piece? Maybe a specific start line piece has the four holes. Yet the box and instructions don't show a start line. Thank you for any help Duncan