I purchased this used machine about a month ago and suspect this may be why it was sold. I think it is a 1994. Has GA17C gun. Came with .030 gas wire. I changed it over to .023 solid wire with bottle. As the title says the feed is not reliable. I am welding auto patch panels with lots of spots and some seam welding. When wire feeds machine works great. I have googled this problem and searched the forums. I also talked to a tech today. Welder has an almost new appearance-little used ? .023 wire feeds through gun with very little effort. I checked the reohstat with an ohm meter-.2-17 ohms. Measured voltage at motor-when the motor starts voltage ramps up to 11volts on the lowest speed setting. Holding the drive wheel with two fingers for a load when the wheel does not turn the voltage on the motor is .52 volts. let go of wheel and motor ramps up normally. I removed the drive assembly and tested the motor with a model train controller and motor runs fine through the speed range, draws about .5 amp and starts at about 3 volts and is unstoppable. Inspected gear reduction, full of grease but none on gears. regreased the gears and reassemble to machine and no change. Service tech thinks it might be the optocoupler on the pc board any other ideas ?? Thanks, Rick.