Ok guys, I got a reply from a Romanian friend of mine, and I think I can share it with you in case somebody else might need it.
Ok, the border is very close to Galati , 18 km. You need to enter 2 km in Moldavia, because Moldavia have the possibility to go with boots to Dunerea river .You will be forced to cross that piece of Moldavian land. This is not a problem whith people, with bandits or something else. Is not a war area (Transnistria and Cecenia is far away). Only if they will ask you visa (I don't thing so) can be a problem. And you will pay 1,5-2 eur tax for motorcycle.
after this 2 km, you will entry in Ukrain, you will go directly to Ismail city. You can cross Kuhurlui (Ialpug) lake on bike, there is a road, no problem.
Until june, we can obtain more details.