I have the GX-E-CS3 with a few personal upgrades for moisture control. These are good little pumps until they are not. Most come from the factory with loose connections on the breaker, the symptoms are the pump will fluctuate in RPMs and shut off for no apparent reason. It is a simple fix to pull the front panel and tighten the screws holding the wires in place. Unfortunately... they also like to spit the wristpins retainer, when that happens it will break into little pieces and jam the cylinder. This is a little harder fix, but very doable for most airgunners... meaning if you can rebuild an FX, this repair is simple in comparison. I just wish the manufacturer to respond to me inquiries. Like what type of grease to use on the cylinder walls!
