The SF2 selftimer has several different settings than can be customized for your race venue. The "min" and "max" dials on the lower left hand corner of the Finish "ZE" unit control the amount of time that the system will allow a racer to be on the course. The following table is taken from the lid of your "ZE" unit.

Values are: (this format does not allow tables so write the numbers down and place them on top of one another)

Rotary dial setting 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Minimum time (secs) 0 5 10 15 20 25 30 35 40 45 50 60 75 90 105 120

Maximum time (secs) 10 20 30 40 50 60 75 90 105 120 140 160 180 210 240 infinit

Setting the "minimum" dial on 3 would then allow another racer to start after 15 seconds.

Setting the "maximum" dial on 5 would clear the time of anyone exceeding 60 seconds and let another racer start.

Start the values high and then dial them in to more closely match your course for maximum numbers of racers participating.