Champion 2000 Inverter Generator will not start

Last week I was dry camping at Bristol Motor Speedway for the races. I was using one of my Champion 2000 Inverter Generators to power my travel trailer while I changed cell phones ect.. When I woke up the next morning the generator was off and out of fuel. I filled the generator with fuel and tried starting it. The unit sputtered one time for about 5 seconds, after about the 5th pull. I tried multiple times to start the generator with no success. I pulled the spark plug and it looked fine but I replaced it with a new one. I tested the volts coming from the plug wire. When turning the motor over the plug wire reads 2-3.5 volts. I also drained the carberator bowl just to make sure the carb was getting fuel. Oil level was also good and the low oil light did not illuminate when trying to start the generator. I re-assembled the generator and it still will not start.

I do service the unit regularly and had done so just before the trip. Oil change, cleaned the spark plug, cleaned and oiled the air filter, cleaned spark arrestor and screen. I also store the unit with no fuel and in a dry place.

Any thoughts?