So, the VIN should be on the steering tube. Regardless, I would put a filter between the carbs and the fuel petcock. One of those universal jobbies you can find at about any auto parts store. You can also use a filter from a garden tractor, they are a bit smaller. Also, remember, a lot of bikes only had a filter on the petcock and no where else. You can either buy the whole thing on Amazon or get the filter out and take it to the m/c shop to have them match it up.
Highfine Replacement Fuel Gas Petcock Valve Tank Switch Pump for Yamaha ATV & Motorcycles 1986-2016,Kawasaki KLF 300 KLF300 Bayou ATV 1988 - 2005,Suzuki ATV LTZ 400 Quadsport 2003-2008