I bought a TaoTao ATA 110 ATV.

When I bought it the guy said it needs a new battery and the carburetor needs to be cleaned because it has been sitting for so long.

I took it home replaced the battery and bought carburetor and intake cleaner to clean my carburetor.

After I finished it put everything together and tried to start it, it just sounded like a car before it starts.

And it wouldn't start.

Then I decided to change the spark plug, and drain the oil and gas then refill it with bran new oil and gas.

Now when I try to start it, it sounds like it does when it has no spark plug in.

I assured the spark plug was connected and connected correctly.

I dont know what the problem could be. Please help.

 

So you went from a state of trying to start, to no attempt at all. I would guess it's more likely that you have lost spark than fuel or compression (since you have not made any other changes). You indicate the spark plug boot was installed correctly, but have you established that you are actually getting a strong spark? If not, there could be several reasons why, kill switch in the off position, rear safety tether not seated fully, faulty spark plug (seen it happen with new ones) remote stop feature in locked mode, or a faulty system component. If you seem to have good spark, determine if the fuel is making it to the cylinder. Other issues could include low compression or valve adjustment.