My bike also has stalled a couple of times from steady 65 mph on straightaway - I've not been fast enough with the RES switch yet.  I wasn't out of gas though so it's probably the petcock.

So I tried the Seafoam suggestion.  Let it sit and restarted.  It idled for a couple of minutes and then sputtered and died.  Same response when I restarted it.  So today, I pulled the carb apart and inspected it.  Clean as a whistle, no apparent problems there.  Put the whole thing back together and it ran again for 2-3 mins before sputtering to a stop even after opening up the throttle to try to prevent it from dying.  

So at this point, I'm stumped and frustrated that I'm not getting to ride.    I guess its back to the shop for my Suzi.  I'll post the results when I know them in case someone else has similar problems that seafoam doesn't help.

Outside of the petcock+ vacumn lines issues (ignoring the carb for a minute)  the other two things that can do this are, (I think) are (1) a leak in the exhaust system or (2)a lousy valve setting job.  The valves have to be done with the engine stone cold.  The exhaust header's two bolts like to loosen up,  and the connection between the header pipe and the muffler ia another obvious places to check.  It sounds like once you hit operating temp, something goes awry.  Best of luck and as always,, please keep us posted.

Have you messed with the mixture screw I did a small adjustment the other day and it did the same thing on my as your saying. I suggest you shut the screw and start again making your adjustments.



just my .02