How can I get the third battery which must leaked, from my BDL 250S?

check with a multmeter if the two poles generator gives the required voltage must be no less than 12.8-13.0 volts at increasing speed and includes stop lights and headlamp reach values do13.8-15.0 volts maximum.If give more than 15,0 volts or small than 12.5 change relay rectifier.

At a a minimum, you will need the magneto (inside left engine cover), the regulator/rectifier (right side, under seat -- has fins on it), the CDI (under seat, at front of airbox), and enough wiring harness to connect the 3. You should put a large capacitor in place of the battery. You will need to jump the sidestand and clutch safety switches, as removing them will cause a no-start condition.

adjust the presure controll to set your evap. coil temp. the lower the pressure the lower the temp.

Matthew, this is a bigger job than a "shade tree" or someone that is NOT VERY experienced. It can be complicated. Sometimes a transmission can be a tough fix! I would ONLY trust this is a factory trained professional!!! Sounds like you have considerable damage!!

I would call BDL and talk to them, when I put the 3" on my pan they were very patient and helpful......changeing the jackshaft is pretty easy.
I suggest getting a manual.