There a good reason why the marine industry started using a gas enzyme product and why Stabil came out with it. Starbrite came out with a product some time back called Star Tron. The reason the old standby Stabil (pink color) no longer worked for long term storage is the damn ethanol they now put in gas. Most of the bike shops in my area and all of the marine dealers now carry the Star Tron stuff, but I think the new Stabil "ethanol formula" will work just as well.

You can read more about the stuff and the reasons for it at http://mystarbrite.com/startron/ .

 

I use Stabil for winter storage; but am seriously considering changing to Seafoam this year, LHP octane booster during road trips, and STP Injector Cleaner occasionally.

 

Never used it in a motorcycle but I used both of these products in my cars until money started getting tight. Come in gallon jugs so you dont have to keep buying it. Use to keep about 12oz in my car for when i filled up. Dont know if it really did wonders but cant say anything bad.
http://lubecontrol.com/fuel.htm