I have an 06' 250 hpdi and use ring free each time I feel up. I understand that ring free is not a gas treatment, but an additive to reduce carbon build up. My questions is why doesn't yamaha create a yamalube oil that contains an additive to reduce carbon build up. My last motor was an Evinrude and the oil I used (xd50) contained an additive that did just that. It would be easier than having to purchase ringfree and add it to the fuel..........I was just curious?? Anyone know.
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