Why is my motorcycle smoking?

I recently bought a 1988 Honda shadow vt800c and now after long rides a small amount of what appears to be white smoke comes from the exhaust pipe. If I turn the bike off for a minute then back on it stops. Could this be from a coolant leak? It is low but I hadn t been monitoring it closely. Also we got gas all over the bike while fixing a fuel hose but washed it pretty well with a hose. Could it be leftover fuel or something?

Exhaust white-smoke has nothing to do with washing off the bike UNLESS you sprayed water into the exhaust.
If coolant levels are good worry about it later.