my experience: after running the bike full throttle(speed 110+) for 20-30minutes, if i try to go for lower rpms, I also get that choking thing. and it becomes normal after some time. Not sure why you get that at 5.5K only
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But as per my understanding, p150 has a microprocessor, which decide about petrol supply as per your need. when you start the bike, it's allowing normal amount of petrol to flow in. Max speed would be around 90 at full throttle. when you keep full throttle for some time, it understand your need of more speed and allows more petrol to flow in and Might be doing other calibrations as well..
now if you want to go back to slower speed immediately, it will have to recalibrate it. and thats why that choking for air sound.
and due to this recalibration and all pulsar gives best average in 150range with power as well when you need it.. cheers!!!
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