Check this out. I was doing my first 5 hr tuneup and discovered dirt inside my carb due to the cheap scrubby pad air filter supplied with my GT5 kit.. Here's some simple steps and a few photo's Items needed. Vacuum bag, scissor's and pen. 1st, lay the filter retainer on the bag and trace. 2nd, cut out new filter insert.. 3rd, Put back together then punch holes for screws. 4th reassemble .... Done! Make sure the new insert is between retainer and the scrubby filter faceing the carb intake.