If you only ran it a couple days just drain and replace the oil, gas and clean or replace the plug and it should start. If you can’t or don’t know how to drain the carburetor it’ll probably take some pulling to clear that out but once you’ve gotten it running it should start reliably.
Best way I’ve kept mine in shape is running some power tools or a shop vac to clean car with them. YMMV, but I use 15-40 Diesel engine oil in mine now.
After almost 16 years?! I ran all of the gas out of the unit at the end of that hurricane season. It would be easiest to just take it to have it checked out and refurbished. I am too old to get into mechanical challenges.