Back up, please.
Do you
hear the pump begin to run when you turn the key on?
(One thing you can do - as an alternative to reading the often wild and prejudicial responses from the internet/forums - is to purchase a subscription to www.cyclepedia.com for your model scooter, and start a service ticket with one of their expert techs! They wrote the Kymco service manuals for KYMCOUSA)
A recommendation for dealing with gas which has sat in a tank for more than a month or two is to fill the remainder of the tank with fresh gas....and ride it!
Obviously ethanol gas is not killing fuel pumps in fneijts' LIKE in 72 hours.
What is the voltage briefly at the pump connectors when the key is turned on?
No voltage?...
look at 10 B (10A)
suspect fuel cut-off
suspect ECU.
Good voltage at the connector and don't hear pump start to prime? Bad pump.
Spoke with a Highflow tech on the phone. He said that their pumps, which match the appearance of the KYMCO OEM pump - are pretty much universal for all kinds of vehicles, incl. boats, motorcycles, etc. They provide sufficient fuel pressure to modern EFI systems. The electrical resistances are most often the same.
I know that I've been using a Highflow pump (sold for Yamaha motorcyles) for 10 yrs in my LIKE200i - and it works great.
The Highflow tech agrees that your issue sounds electrical - not fuel related.
You are buying which brand pump? Paying how much?
Good Highflow is @ $85
Stig