not getting fuel to carb on Onan generator

I had that exact same symptom a few months ago. I cleaned out the air filter, fooled with it some, checked the plug gaps, really did nothing meaningful.. And when I put it all back together it started. Give the little choke lever a wiggle before you hit the start button. Also, sometimes I will need to adjust the altitude setting under the float bowl and when she starts turn it back to where it was originally. My old Onan almost never starts on the first try when it's been sitting a few days. I hit the start button, wait about 30 seconds and then she fires right up pretty much every time. My mechanic just shrugs his shoulders.. As long as I have a working generator, I don't really care. I use that thing on pretty much every trip we take, especially in hot weather to run the roof air.