Motorcycle Repair: 1984 Yamaha Virago XV700, platinum electrode, piston damage

Question
I'm looking at this bike to buy.  Has 14,080 mi.  Runs great, but fouls the front sparkplug when driven any distance.  Is this a common problem, and what are the possible causes/solutions?
Many thanks,
Berry

Answer
Berry,

-fouling the plug could be for various reasons.
-Is it dry black fouling or wet oily fouling?

-Dry fouling is an overly rich fuel mix or lack of air.
check the air filter. Check choke.
-Oily fouling could be valve seals, but more
likely bad oil rings or piston damage.

-A plug might foul if the TCI or transistor
ignition had a problem but usually one of the
cylinders will stop firing completely.

-the Virago is a good bike but is getting
fairly old. Some have had problems with
the solder getting loose on the ignition module
electronics. Also the carbs have small screens
near the float valves that plug up.

-try a plug with a small platinum electrode,
they resist fouling.

You may need to rebuild the top end soon if it is
wet oily fouling.