My Yamaha EF30iSEb, as modified by Us Carburetion in WV to run on propane, LNG, and gasoline as well as added a remote start feature, was found DOA when I was preparing it for our trip south for the winter. I had let the battery go dead and it would not take a charge. The generator would start on a single pull as always, but would not charge the battery over 7 volts. Removed the battery and it would not charge on my charger either. Since the unit was out of warranty, I was off to the local motorcycle dealer and bought a replacement.
Not watching what I was doing, (battery not well marked) I hooked up the terminals backwards and there was a sharp "pop" when I hooked up the ground lug. Realizing my error (too late of course), I hooked it up correctly, but nada. Would not start on the pull starter either.
Sadly I was forced to call US Carb with my problem. Shawn, from Tech support, was awesome. He told me how to find the fuse located in the guts of the generator that protects it from dummies like me. So, after changing the fuse, the generator started right up using the starter. However, the remote wireless starter receiver was fried. Shawn decided that even out of warranty, the receiver "should have been protected better" and covered a swap out under warranty.
This unit was expensive, yes, but the support after the sale has exceeded my expectations EVERY time I have called them. Big Kudos!