The guy at West Marine said Star Tron Enzyme Fuel Treatment would provide the same (or better) results as ringfree. I have a 2002 2320 with a Yamaha 225 four stroke that I purchased a few months ago. So far I have not added anything to the fuel, and I do not know if the prior owner did. The motor has run great, and I hate to mess up what's not broken. Should I start adding this Star Tron product, or ringfree, or nothing?