Throttle issue

I have a 125 Suzuki ATV.... When I throttle it any, it dies. But, It will idle fine. What's the deal.?

The main jet in the carburetor is clogged. Its easy to fix. Remove the carburetor and carefully unscrew the float bowl. You can see the main jet. It should have a needle attached to the throttle slide that goes in and out of the main jet when you open the throttle.
Spray some carb cleaner into the main h=jet and also around the float bowl to clean out any residue.
Then reassemble.
You might want to get a service manuals so you can see instructions on how to properly remove and disassemble the carb.