Oil filters are a funny thing. I used to own a Yamaha as well and it had a standard filter which was used by numerous other motorcycles and small engines. The issue is that each bike is differenct. For example, most Toyota´s use a similarily sized filter but the flow design and build of the filter is such that someonelse´s filter may fit but not function correctly. I used to own a Honda XT 600 which if put in backwards (not hard to do) would restrict oil flow and starve the valve head of oil. There are other options. There are a couple of all metal filters (costly up front but re-useable which may work for you. I look at it, for the cost of a $6 filter, I have peac of mind and more importantly, if something does go wrong with the motor, SUZUKI can NOT use the excuse that you used non-approved parts. I have over 16000kms on mine really enjoying it. I do change the oil more often than is asked for by SUZUKI and so far it´s been cheap to run (oil change with filter from the dealer is only about $45). Not bad.