starts off good and then fades

[buckshot35]

kart starts off good runs with the lead pack, but as the run goes on the the kart goes backward but the fasted laps are at the end of the race. looking for feedback on why.

 

[flattop1]

More internal prep.

 

[Burris Racer]

kart starts off good runs with the lead pack, but as the run goes on the the kart goes backward but the fasted laps are at the end of the race. looking for feedback on why.

You're asking the question in the dirt oval forum so I'll assume that is accurate. What engine platform, what brand tires, how much faster are you running at the end vs the beginning of the race?