Pump may be bad. Also injector could be clogged. Also could be electrical. Several inmates have had problems with bad rectifiers or poor coil connections.
I had one ride where bike kept stalling out and ended up being loose coil connection but seemed like a fuel issue.
2009 KTM 690r Enduro SOLD
2002 RC51 SOLD
2010 KTM 990 Supermoto R SOLD
2014 KTM EXC 500