A month before, the carburetor of my Sprinter were started choking (due to impurities in Petrol tank). Symptoms were like bike having suffocation on acceleration. [Just to clarify the carburetor is in healthy condition and it is not badly choked but slightly).
I consulted my mechanic and he agreed to me that carburetor was choking. I was like do we need to open the carburetor. He told me No. There is a quick way to do that.
He just turned the fuel knob to off position and took the air pipe (the fat one just above the mixture screw) as shown below.
Using the gun he pumped air with pressure, in result petrol came out of the air filter box and some amount of petrol went into the valve area in the head. Waited till the petrol stop coming out of the filter box. At this moment bike was in over state. It took 5 - 6 kicks before it started and then we turned the fuel knob to on position. That's All.
I was in disbelieve at that moment. Later on I was happy. It did the work. Its a month now and no choking issue yet, very smooth ride.
I again asked if there is any damage done this way, mechanic said no it is completely safe.