Mower will not start unless I spray starter fluid

I have a HRX217 Honda, I just replaced the carburetor, changed the oil, new air filter and spark plug. The mower will not start unless I spray starter fluid. It wouldn't start at all, now after all the above it will start but only with starter fluid, then it runs until it is killed and will not start again unless I use starter fluid. I have read that it may be the automatic chock, how would I change that? The mower is about 4 years old, I have only had it two years, the first two years a lady had it and never used it, but let gas in it for two years. I took it to a shop and they got it running for about a 2 years. Now all this trouble for me.