my blaster was doing the same exact thing.... it feels like it lost power correct? if so this is what i did to resolve my problem. first i cleaned my air filter opened up the carb and my main jet was not all the way turned in which didnt allow enough fuel/gas to get into the motor...i would definately check that out and make sure the float is the correct height.
Marco,
Follow The parking break wires from the clutch lever to under the hood and disconnect them at the plug. If you have not already tried. Then try and start it again.
I would bet the bike was parked and the gas remained in the carb. My strong opinion is that the problem is in the carb. Two year of gas will leave varnish depsits in the carb. The last Blaster I bought had been sitting five years. I had to soke the carb in a carb cleaner/acid cleaner. In the US, you can buy the cleaner kit at a local auto parts shop. It is a one gallon metal can filled with a mild acid.