GET A TRANSPARENT GLASS BOTTLE, WHICH HAS cc MARKED ON IT. SUCH A BOTTLE WITH cc MARKED UP TO 200 cc IS AVAILABLE FROM HOSPITALs, WHERE IT IS USED FOR FEEDING "drip" TO PATIENTS FOR BLOOD OR SALINE. GET SUCH A BOTTLE. THEN GET A TAP, (Like fuel cock of tank) FITTED TO ITS LOWER END (maybe you can use Mahindra M-seal for this). NOW ATTACH A RUBBER or FLEXIBLE PLASTIC PIPE TO IT (with circlip to prevent leakage), SAME AS LIKE THE NORMAL RUBBER / PLASTIC PIPE WHICH GOES FROM FUEL TANK TO CARBURETTOR. THIS PIPE HAS TO BE @ ONE METRE LONG. IT IS KWITE KOMPLIKATED TO MAKE THIS, BUT NO OTHER WAY. THEN FIT THIS BOTTLE INTO A HOLDER WITH CLAMP, SUCH THAT THE cc MARKS SHOULD BE ABLE TO BE SEEN CLEARLY. NOW FILL PETROL INTO IT, KEEPING ITS COCK CLOSED OTHERWISE PETROL WILL DROP AND FLOW OUT (without your realizing) AND GET WASTED. FILL PETROL TILL @ ONE or TWO cm ABOVE (==more than) THE TOP 200 cc MARK. THEN CLAMP THIS FILLED BOTTLE EITHER TO SOMEWHERE ON THE BIKE OR TO YOUR BODY AT A LEVEL WHICH IS AT FUEL TANK LEVEL OR HIGHER, BUT MUST BE ABOVE CARBURETTOR (so that petrol can flow out by gravity). NOW KEEPING THE FUEL COCK OF THE FUEL TANK CLOSED, PULL OUT THE FUEL PIPE (which goes from tank to carburettor) FROM THE NIPPLE, AND FIT THE LOWER END OF THE PLASTIC PIPE (which is fitted to bottle) TO THE PETROL INLET NIPPLE OF THE CARBURETTOR FROM WHICH YOU JUST TOOK OUT THE PIPE. NOW RIDE THE BIKE FOR @ ONE or TWO km SO THAT AIR BUBBLES (if any) GO OUT FROM CARBURETTOR, TUBE and BOTTLE, AND THERE IS CONTINUITY OF PETROL RIGHT FROM CARBURETTOR FLOAT CHAMBER, THRU PLASTIC PIPE AND UP TO PETROL IN THE GLASS BOTTLE. THIS RIDE WHICH YOU JUST DID, IS CALLED THE CONTINUITY RIDE. YOU CAN BE SURE THAT THIS CONTINUITY OF PETROL HAS BEEN ACHIEVED ONLY IF THE LEVEL OF PETROL HAS GONE DOWN BY @ MORE THAN ONE cm FROM THE LEVEL TO WHICH YOU HAD FILLED IT IN THE BEGINING. NOW AGAIN SLOWLY AND a-Q-rately FILL PETROL INTO THE BOTTLE EXACTLY UPTO 200 cc MARK, NOTE DOWN THE ODOMETER READING (THIS IS THE STARTING READING) AND START RIDING THE BIKE.
RIDE A FEW km AND STOP. BY LuuKING IN THE ODOMETER, YOU CAN SEE HOW MANY km YOU HAVE RIDED (THIS IS THE ENDING READING). BY LuuKing AT MARKINGS ON BOTTLE, YOU CAN KNOW HOW MANY cc PETROL HAS BEEN CONSUMED. CONVERT THE cc OF PETROL INTO Litres BY DIVIDING THE cc BY ONE THOUSAND, BCOZ 1000 cc==ONE litre.
NOW DIVIDE kms YOU HAVE TRAVELLED (noted from odometer or trip meter, which is the difference between the STARTING READING and the ENDING READING), BY THE Litres OF PETROL CONSUMED, THAT GIVES THE a-Q-rate MILEAGE / AVERAGE FIGURE IN kms PER Litre.