Hello Nireen and welcome to the knowledge bowl of the Kymco world, otherwise known as the Kymco forum. Lots and lots of good information collectively found here, concerning Kymco vehicles Not trying to be a wise guy, but to answer your question on how much mileage is to much on a DT300i. The only correct answer would be, when the rod breaks or seizes on the crank shaft and that won't happen unless it is run without oil. With proper maintenance, I would guess 80 to 100K would not be out of the question. Cheers
Mac