Possibilities that come to mind are: Blocked main jet. Broken needle from wear. Blocked filter. Other fuel tap/line restriction. Faulty fuel pump (would be worse at low tank level?) Float/needle issue. Carb vent filter blocked? I once had a bad electrical connection that acted like a blocked main jet. Would idle ok but die under throttle. Finally the wire broke off completely, killing other stuff and giving the game away. I try to get parts locally (WA) from Savage KTM, or from whichever online KTM store has my bits in stock.