If you want to upgrade to a nicer cleaner looking installation go to Manic Mechanic's webpage on the right of your screen under the sponsers column .
He has some good replacement options . Or put your kit's standard sprocket on your back wheel , the correct way so that it is snug and runs true with the wheel , and moniter it occasionally so that the bolts stay snug , and go about your business having a good time riding . There are many ,many , bike builds using the standard kit sprocket . Monitering all the bolts in your entire assembally is a good idea .