(Initially i didn't know about the oil limit in passion plus) I accidentally filled 2 Litre engine oil in my Hero Passion Plus Motorcycle, which is more than specified limit (1 Litre). With that excess oil i rode bike for about 20 meters, then bike stopped and didn't start. After realizing my mistake i removed the excess oil my Motorcycle,now my motorcycle starts for some time and then stops automatically, and Lots of Black smoke coming from silencer. I notice that some oil is leaking at the bottom of the engine where silencer is attached. i want to know whats happening to my motorcycle, and get a rough idea before going to the mechanic. (Because mechanic may fool me and can charge me extra money)
As you overfilled the engine, the oil has got into places in volumes where it should not.
Either it may clear itself over time,
You will have to remove some parts - such as the exhaust downpipe, and clean them.
If you have to take it to a mechanic then you will have to pay for the time taken as is normal...
First thing to do is remove all engine oil from the motorcycle. While removing engine oil please wait for 10-15 min. to ensure complete oil is completely drain. Then fill aprox 900ml oil in engine. As some part of engine oil remains in engine itself.
After doing this your problem should be solved.Ride motorcycle for few kms and observe for black smoke from exhaust.If it continues even after riding for ~10 kms then consult your mechanic.
(Your observation of black smoke from silencer indicates that engine oil is burning along with Petrol.)