2012 America Efi Pippin N Fartin

Hi everyone. Time again to ask for technical help.
Had my 2012 America efi now about 18 months. Since ownership, A very, very occasional problem occurred for the 4th time again yesterday,
Seems to happen when going down hill, no revs (overrun)
Feels like it's run out of fuel, no response when trying to rev, keeping it in gear pleading it to start up again, it pops n bangs, feels like explosions from under the seat, like its back firing through the air intake. Then it restarts and carries on with no further episode for the next few months. Couple of times pulled over and it has restarted on the button! Frustrating.
Fuel levels have been fine each time. Like I say, it is such a rarity it's one of them jobs you can't really fault find.
Just asking if anyone has had a similar issue, and how it was cured.
Thanks in advance for any help

 

Hi. The she idles fine, not had throttle bodies balanced since I bought it. So no idea if or when they have been balanced.
Occasionally again, when pulling off it will stall.???

 

Thanks. Will give it a try