I have a 01 arctic cat 250 4x4 (green). It has a mikuni BST31 carburator. Does ANYONE know if there is an aftermarket or different carb that can be fit to the 250. It seems the BST31 can not be found in a rebuild. It NEVER started cold from new and lacked power even before it needed repair. So if possible I would like to put something else on it. If not, does anyone know if a bigger main jet on the BST31 will help with the cold start or power issue.