Front cylinder cuts out after running

External Since: Jun 29, 2003 Posts: 6

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.

External Since: Jun 21, 2003 Posts: 661

>From: hobbes17.RemoveThis@mail.com (Michael)

>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.

Could be the ignition coil heating up and opening up when it gets warm, or an
electrical connector that gets hot and stops the flow of electricity to the
coil, in which case it would suddenly quit firing on one cylinder.

If it wheezes and runs faster just before it quits it might be fuel starvation.
It could be the idle jets and idle screws and orifices in one carb are plugged
up or the fuel shut off needle valve on the front carb might be gummed up or
the float level may be too low.

Or maybe the valve clearances are set too tight, and the
front cylinder looses compression when the cylinder gets hot and the valves
don't seat.