XJ700N After riding about a mile today I turned a corner and the bike stumbled and then shut down. Acted like it was out of fuel when trying to restart it, but the tank was almost full. Moving petcock to reserve didn't help. Finally, I moved the petcock to Prime, waited a minute and it fired up. Just to check I moved it back to run and in about a minute it shut off again. Put it back on Prime, got it started and rode home (8 miles) with no futher issue. At home I checked the vacuum hose and it seemed to be ok and I made sure it was seated at both ends. Set it to Run but could never get it to shut down again. At first I assumed a bad petcock (rebuilt about 5 years ago), but now I am thinking there is a problem with the vacuum. I am using a long piece of vacuum hose (not fuel line) trying to avoid it kinking, but that may have happened. The clamps are not particularly tight, but with the vacuum this engine pulls I can't see that being the problem, although I will replace them and possibly the hose. Has anyone ever considered using a "U" shaped piece metal tubing to make the turn in the vacuum line?