Complex sentence: Since 2004, the "Lilly Belle" did not run in regular operating service due to its pony truck spreading out the track and knocking it out of whack and frame issues that caused it to tear up the whole tracks when run for extended periods.
Split into simpler sentences: Since 2004, the "Lilly Belle" did not run in regular operating service due to its pony truck spreading out the track and knocking it out of whack. It also had frame issues that caused it to tear up the whole tracks when run for extended periods.