I have one.. great little unit.. very reliable..I am a wannabee diy guy.. so good luck1 assuming sparkplug is good / in / /newish??Fuel needs to be filled.. I suggest premium only (less residue if it sits for long.)fill oil.. top up..d/c electric plugsthentogle ignition switch to onturn fuel cap to onturn fuel switch (sw) to onmove choke to start if engine is cold start.pull starter cord ..good luckps.. I have learned to run engine dry of fuel after use. turn off fuel (sw).. this empties carb.. You may have to pull starter cord a few times with next start to bring the fuel down..
Within the last month I had a customer that had a very similar problem. He had the GCU changed out and STILL had the problem. He ended up changing the inverter on a 5000W unit. Total parts cost was almost $700.00 {300.00 GCU and $410.00 Inverter) PN 7228-D21007 INVERTER UNIT ($410.44)
Since the actual generator is DC you should check for a DC output from the generator and watch the DC voltage as it goes into overload. If the DC voltage exceeds 130VDC I would suspect the GCU. If it stays around 120 VDC and still goes into an overload condition the inverter is bad.
A video of this generator is here:
Sad part of it is when new it retailed for around $500.00. They have been discontinued but there is a semi-clone of this unit by Eastern Tools ETQ IN1800i http://www.amazon.com/IN1800I-4-Stroke-Portable-Inverter-Generator/dp/B001JLTH12 ($280.00)
This information provided so you can make an informed decision about repair or replacement.
Ebay has the carb for under fifteen bucks. Want to add a note on calibration or recalibrating when replacing the carburetor. McCulloch FG6000 or FG5700, Wen, and many more use the same wenling jennfeng (wenling jenn feng) engine. On the FG6000, FG5700, and others, you'll see both an idle speed screw and an idle mixture needle valve on the carb. On top of the engine, you'll see the governor sensitivity spring tensioner screw top center of engine. First, loosen the governor spring tensioner screw until its loose with spring totally collapsed. With no load, adjust carb idle to 60hz-62hz using a multimeter. Now adjust the carburetor needle valve to the highest smoothest idle speed (highest possible hertz on the multimeter). Then readjust carb idles speed screw back to 60-62hz max, nothing higher. Finally, adjust the governor spring tensioner screw to calibrate governor sensitivity; loosen for less governing, tighten for more governing, and too tight will take away and defeat idle speed screw on carb. It's a delicate balance, takes some work, but when finished the generator should always maintain 60-62hz under any load condition.
