what would it be ?
last week my banshee was running great, then just before turning it off it began to work bad.
i was low on fuel so i thought that could be the problem but ,now i fully tank it and it stayed the same .
it just doesn't start....(disapointed).

i have some issues with the o rings of the head (slips water out).

i have tried:
choke fully open+trotle wide open (carb overfload)
choke full open/half (carb overfload)

and it just doesn't start..... helppp

 

Sounds like you could have picked up some trash in the bottom of the tank and the carbs might need to be cleaned. Probably trash in the needle valve not allowing it to close and therefore flooding the engine.

One thing that I would be sure to check is that leak you talked about on the head... That needs to be fixed asap...
It could be letting you loose compression and would then make it harder to start as well. Do a compression check and see what your pressures are. If they are low you are either loosing compression there or you are ready for a new topend. Both of which would cause you to have hard starts.

Just some things to check... Good luck with it.