Hi
@renato pasion - For the cert rides, the extra gas can is fine. Secure it so you don't lose time pulling the can off to refuel. On your fuel log, you must account for all fuel used and still maintain a DBR every 350 miles or less.
When I did my SS1k ride on my 150cc scooter, my stock range was only 100-110 miles and the scooter only has a 2.1 gallon tank. I took a 2.25 Gal fuel jug with me. With some exceptions, every other fuel stop was on the road side with the jug. My fuel log states "on road fuel" for the times I used the jug. I still log the date, time, time zone and miles from last stop on the log. When I fill only the main tank at a gas station, I make a note of that. Otherwise I note that I filled both tanks or tank and jug. This helps document my mileage between gas stations and between all refueling stops. I added a note explaining this at the top of the fuel log page. When I filled at a gas station I filled both the main tank and the jug and my receipt accounts for all of my fuel as per IBA rules. In my case, even with the jug, I was in no danger of exceeding the 350 range between DBRs.
At one point in my ride I realized that by stopping earlier than planned, I would be able to fill only the main tank then, but would skip another fuel stop that was farther off my route, thus saving time. So I have that one stop that just says "main tank only" with time, miles, etc. My particular route had zero gas stations on the actual route.
Good luck and have fun. Document all your stops for fuel, by the road or at a station. You don't need a separate receipt for filling the jug, just fill the bike and the jug on one receipt. Note filling both on the fuel log for that stop. It makes it clearer to the verification team.