The PDF rulebook version can be found at: http://www.hrkc.com/rules
8.1.1 All race entries entering the racing surface during race day must have a working transponder mounted on them. This includes all three rounds (Practice, Heat, and Feature Races) If the competitor owns their own AMB/MyLaps Trans160 or Trans260 transponder, they must include the transponder number on their membership form or inform HRKC so that they can be entered into the scoring system.
8.1.2 It is the racers responsibility to make sure that the transponder is affixed to the kart/kar prior to entering the racing surface for each Practice, Heat, and Feature races. Once on the track the kart/kar may not be stopped for a transponder to be added. Entries without transponders are not scored for the race.
8.1.3 The transponder must be affixed in the approved holder on the kart steering column (except for all Champ Kart classes where it is fastened to the left front nerf bar). Placing a transponder anywhere on the driver is prohibited.
8.2.1 The official in charge of scoring shall determine the finishing race position using both the transponder system and manual line scoring.
8.2.2 Failure to pick up the transponder signal by the electronic scoring system will prevent the competitor from being timed for qualifying or scored in the race. However, if a transponder falls offs of the kart/kar or fails to function during a race, the Race Director may contact the finishers immediately in front of and immediately behind the non-scoring entry and consult with the other race officials to verify the finishing position. If the position can be verified, the Race Director can award the nonscoring entry its correct position.
8.3 Transponder Rental
8.3.1 Competitors that do not own transponders may rent one from HRKC when registering at the ticket window prior to each race. Transponder rental is $10.00 per day.
8.3.2 The rental transponder number is assigned by HRKC during driver registration. When members that rent a transponder each race of the season (repeat renters), effort are made to ensure the competitor receives the same transponder each race.
8.3.3 Transponders shall be visible so they can be easily retrieved by the scales attendant after the feature. If a rental transponder is indicated on the registration sheet used at the scales, and the transponder is not turned in, the scale attendant will not annotate the weight and the driver will not be scored or receive points.
Bottom line: if you rent a transponder, turn it in at the scales after your Feature Race.