Motorcycle Repair: white exhaust smoke, cylinder head gasket, blown head gasket

Question
My 1997 Thunderbird is blowing white smoke today.  I have been starting it up
all winter to keep the battery charged, and today I noticed white smoke from
exhaust.  I  didn't let it get warmed up, wasn't sure if this was a sign of a
problem.

Answer
White smoke coming from the exhaust is normal for the situation you've described. When a bike is stored for long periods of time - especially if in an unheated garage - condensation forms inside the motor due to temperature changes. This moisture gets burned off in the combustion chamber, resulting in white "smoke" coming out the exhaust. Once the motor is up to operating temperature, the smoke usually disappears. Short, infrequent warmups during winter storage will result in a lot of condensation getting inside the motor.

However, because your bike is liquid cooled you will also need to check if the cylinder head gasket is blown, as this will allow coolant to leak into the cylinders and result in white smoke. In extreme cold weather there is also the danger that the coolant has frozen and cracked a cylinder wall, which is much more serious. Check the oil tank, if there is foamy, whitish coloured oil on the dipstick you have either a blown head gasket or a cracked cylinder wall that needs replacing.

BTW, I used to own a '95 Triumph Thunderbird. Nice bike!