A very important component in your custom airsoft build is about your gear set and Airsoft GI talks precisely about that in this episode of their "Building Your Build" series... "This is the episode of Building Your Build that you have been waiting for and we have been dreading! We finally get to shimming the gear set and adjust the motor height. This is the longest and most tedious part about upgrading an airsoft gun. Though it is mind numbing, once completed properly, the efficiency and performance of your airsoft gun will improve dramatically! Especially if you upgrade to an upgraded gear set. This video was made as a guide to help you learn the process of how to shim your gear set. Keep in mind all gear sets and gear boxes are made different. How I shimmed the gears in this video may not work for you. Do some research before attempting!

DISCLAIMER: Do not to any of the upgrades in this series to your airsoft gun if it is within its warranty period. Any of these modifications / upgrades will void your warranty."