Could you post up a picture of the oil filter? Anyways, it sounds like your floats need to be reset. Another thing to consider is your jetting. If the bike was jetted for summer weather and your riding it in the sub zero tempetures, you are going to burn it up. You need to rejet the bike for colder temps. The first thing I would do is pull the carbs, (one at a time) and clean the pilot and main jets out real good and rejet accordingly. Then reset your float level. If that does not stop the gas from over flowing, you will probably need to buy a rebuild kit. Give us a list of your mods, air temp and elevation and we can help you determine what jet sizes you need.