If it is a two stroke so have you kept your oil topped up.
This mixes in the engine and so all you have to do is keep topped up. Really important. I am sure you have but I have to ask.
The fuel leak- Where is it coming from? The carb? Be worth trying to find out and letting the forum know and someone may be able to help.
You also may need a decoke of the pipe you wil lose power if this is the case.
BB
September 2009