About 1 month ago my Duke 390 engine would stall when down shifting and then would start again. 1 week ago my fuel ran out and I couldn't restart after adding more fuel. Bike was loaded on to truck and returned to my home (2 hours). Upon unloading bike out of curiosity I attempted to start it. Surprise it started and ran OK. Next day I rode 20 kms to have new rear tire fitted. No problems. After tire fit I returned home. Alas half way on return trip engine died and would not start. On attempting to start, motor would crank and backfire but wouldn't run. Question: Is this a FUEL problem. Dirty fuel filter? Faulty fuel pump? Your advice much appreciated! By the way I am in Vietnam and language barrier is a problem.