Scooter starts but stalls when you give it gas

[AylmerFreerider]

Hey all,  friend of mine pick up a scooter and he thought is was an easy fix.

The scooter starts every time but sputters at about 1300-1500 RPMs, but as soon as you try to give it some gas it stalls.

So things that have been done:
New spark plug, New Carb, New coil, New gas (super of course),  all grounds checked.

Now for some reason it worked for a day with no issue then the next day back to sputtering.  Caveat here is that is a 137QMB and not a 139QMB(GY6)

And ideas appreciated

[hundacobra]

it might be your fuel filter . and have you check for spark , make sure it was strong not weak(cdi might be going out).and have you tried adjusting the carb could be running rich or lean .you also might be having leak around your engine gaskets or your lines . with it running see if you can some or here any odd sounds or feel air being pushed out (and not from the exhaust lol) lmk if any of this helps and report back with what you find  so we can go from there..

[AylmerFreerider]

it might be your fuel filter . and have you check for spark , make sure it was strong not weak(cdi might be going out).and have you tried adjusting the carb could be running rich or lean .you also might be having leak around your engine gaskets or your lines . with it running see if you can some or here any odd sounds or feel air being pushed out (and not from the exhaust lol) lmk if any of this helps and report back with what you find  so we can go from there..

Turns out the CDI was defective.  Running well now.