Too much thinkin

I would replace the piagtail (plug),bulb and battery, check the charging voltage and ride the bike.

David

 

Like some of the others stated this does not applyhere. Where it does apply is to situations with motors and many IC chips.

& Like the others have said bloated battery is often a symptom of overcharging from bad voltage regulator.

So definatly change the battery and plug and then moniter the voltage with the bike running.

Cheers Jim

 

There may have been a short cct at the headlight connector (burned connector). This would cause a serious current draw which would prevent the starter from functioning properly (bike souldn't start), heating the battery to the point of failure (swollen battery). You would think though, that a fuse would have opened.
Perhaps pinched wires in the headlight area?