Front cylinder cuts out after running

Looking to see if anyone has any idea what is going on here.
Generally my bike starts up fine (it's a yamaha 84 virago 700) And you
can tell it's running fine on both cylinders by the way it starts,
plus it's piped, so you can hear it. After a while of running the
front cylinder will cut out, if i stop, shut it down and let it sit
for a minute usually it will start up on both cylinders again. I
pulled the plug and it hasn't fouled at all, and the rear cylinder
always runs well. What could cause it to cut out like that. Is
something clogging the carbs just enough that the front cylinder isn't
getting enough gas at high rpm's? Doesn't make any sense to me, in
any case usually once it's been running a while it stays running, and
i don't have any more problems till i stop for a day. Any ideas are
very welcome, thanks for any input.

 

Had a similar intermittant problem with my ol' Kawi - - coil wire/cap at
the coil-end was iffy. One coil runs two cylinders (in-line 4), so I'd
lose my inner two... When the bike completely heated up (like 20 miles
from anywhere), the wire/cap expanded and lost electrical contact.
Drove me crazy after the compression test (in-line 4 again, and of
course it was the inner cylinders), spark test, coil test, etc. Check
the coil cap(s) at the coil-end, even if your bike shares a coil for the
two cylinders (geez - - blonde moment - - a 700 Virago is a twin,
right?). Repeated tightening finally *quit solving* the problem
temporarily, but a new coil wire assy. fixed it.