Hello asking here since there are no 250 owners in SA it seems. In the states the guys do a mod (along with the washer under the needle) where they drill the bleed hole in the carb slide to improve throttle response. Working from inches to mm's one needs a 2.75mm drill for the hole. I can only find 2.8mm drill bits for sale locally. Not sure if it's close enough ? I don't even think you get a 2.75mm drill !