Im looking to buy a used kart for for some Street fun. My brother and i are going to build a small dirt track on his property at some point.i have been looking for something i could take on the dirt track oval as well at some point.im looking at a go kart that has a tag leopard 125 cc engine water cool.also im lookin at a kart w Kt 100 .as far as maintenance on these engines.which is the more durable and suitable for street and dirt?