I fill the bikes with non ethanol, add sea foam, run till the engine stalls out with petcock closed. Leave it all winter with battery in on trickle charger, both bikes, carbed, fire in the spring as new. The sleds just fill and add se foam, sme thing, fire right up in fall, they are fuel injected. It has been working for me for years and I see no use in trying another way. I have not cleaned a card for a very very long time. Maybe I would get the same results with nothing, but for5 bucks per unit, why f around.