If its actually low throttle settings instead of low engine speeds, I'd try cleaning the carbs and adjusting the settings. (mechanics.stackexchange.com)
Four settings (comfort, sport, sport plus and individual) alter throttle settings, steering, suspension and the like. (autoweek.com)
Jeep's Selec - Terrain 4 × 4 system lets the driver tweak torque and throttle settings for sand and mud, rock, snow or «sport» by turning a dial. (bestride.com)