Do I need to treat E10 fuel?

[Telliedog]

I used to add Ring-free to my fuel for a Yamaha 150 HPDI. Do I still need to add any summertime treatment with the new fuel? From what I understand the ethanol is far more of a solvent so there should be no issues of varnish buildup or anything of that nature.

Any thoughts? Thanks a ton.

[FireFly]

I used to add Ring-free to my fuel for a Yamaha 150 HPDI. Do I still need to add any summertime treatment with the new fuel? From what I understand the ethanol is far more of a solvent so there should be no issues of varnish buildup or anything of that nature.

Any thoughts? Thanks a ton.

If you have been using ring free I would recommend you stick with it. I don't think the E10 will do anything to thwart carbon deposits.

[Go Fish]

FireFly is right on.

The ethanol in the fuel is added as a source of oxygen to aid in the combustion process and takes the place of MTBE in the old gas formulations. Under the conditions in an internal combustion engine the combustion process is never completely efficient (even with the additives) and some unburnt fuel remains in the cylinder. The remaining fuel (and oil in 2 strokes) is responsible for the growth of carbon deposits.

Ethanol will most likely dissolve the brown "varnish" deposits but it is not a solvent for carbon. In fact, not many things, other than strong acids, will effectively dissolve carbon.

Ring Free and the similar products contain oxidizers that begin to chemically "burn" or oxidize the carbon deposits in your motor. The products of the chemical reaction between Ring Free and carbon either combust with the fuel on a power stroke or are swept out of the engine on an exhaust stroke.

Keep using Ring Free