spark plug cap arching when not attached to plug normal?

[davemjeffery]

hi there

ive been having some issues with my 1990 fzr600 i pulled the spark plug cap off an noticed it was arching from the plastic cap to the engine frame anywhere that was close is that normal ive never seen that before ?

[DonTZ125]

It was arcing AFTER you pulled it off? I would definitely expect it to arc out the bottom - 40 kajillion volts is 40 kajillion volts, whether it's through the plug or through the cap. If it's going sideways through the plastic, it's time for new caps.