i have a 1997 scrambler 400 4x4 that i have been having some problems with,sometimes it will have good spark sometimes weak spark.The battery that is in it is not really good,i have been using a battery charger to jump it,could that have anything to do with it,also when i got it started up the other day when i revved it to high rpm it actually blew up the headlight bulbs.any ideas on what would cause that

 

over charging, too much voltage from the recifier. imo

 

Had the same problem with my 400L a few weeks ago. A new battery fixed it.

 

if your battery is no good and wont charge the power will go somewhere by by lights