SKUSA lists two carbs, the PWK with the round screw top and the PWM with 2 screws to retain the top, as legal for the Stock CR125 classes. Each has its advantages and trade offs. The PWK offers very linear part throttle response that helps controllability when exiting slow turns. The PWM gives slightly more mid range power but a more "sudden" part throttle response.Tight twisty tracks that require strict throttle discipline tend to favor the PWK, while tracks with high speed turns and mostly full throttle accelerations through the gears will favor the slight mid range power advantage of the PWM.
Expert drivers turn lap times that are virtually the same on most tracks with either carb. However, novice and intermediate drivers will probably see differences in lap times between the PWM and PWK especially on the more technical tracks.
SRS Stock 125 power can put you in the front pack, tuning choices such as which carb PWK or PWM determines who wins. For more detailed information about SRS Shifter Kart engine recommendations, call us at 903-769-4140.
