three cyl only

[KatCroatia]

i tried to start my bike and it started right on press of a button but worked wierd, i noticed some claping sound and i touched exhaust pipes, one was cold after 2 minutes of working, i revv it and black smoke was getting out, it poped from the exhaust and 4 th cyl started workin. what could be the problem?
sorry for my bad english.

[Icepaws]

fouled plug...

[KATANA-BRASIL]

Check your electrical system until your spark plug cap, check your spark
Its happened with me and was spark plug cap replaced and functions perfectly again