2018 50cc GY6 moped starting issue

[bigz1983]

I have 2 Mopeds 50cc GY6 made in 2018
One is green and the other is black.
The black moped starts fine.
The green moped will not start unless I put a shot of starting fluid into the carburetor.
Last year summer of 2020 I replaced both carburetors and put ethanol free REC 90 gas.
Could the carb need replacing again?

[mvdc1980]

I had a cy 50, and did the same thing. Looks like some sort of compression issue. If not magneto misalignment, loose wire to cdi ie weak spark.

[whiteGIANT510]

The valves come too tight out of the factory. It will run for 20 ton60 miles then it just won't.

[whiteGIANT510]

And mopeds have pedals. You have scooters.