oil in left cylinder exhaust header

[79vetteguy]

HI, Need some help/advice--I have noticeable oil present in left cylinder exhaust header pipe after riding a short time. I do not see smoke from end of exhaust at start up or when running. I do see smoke after turning engine off--smoke exits at joint between header pipe and exhaust pipe.
Bike runs pretty good for an amateur mechanic--left cylinder actually seems to have less plug fouling problems than does the right side.
All help will be appreciated---love my old Super Hawk.
Thanks