Motorcycle Repair: White smoke out of exhaust, exhaust, smoke

Question
I have a 74 honda CB750K with alot of white smoke coming from the exhaust. What is causing this problem

Answer
Are you sure the smoke is white? White smoke is usually caused by antifreeze burning, but since the 750K is air cooled we can eliminate burning anti-freeze right away. I am going to assume the smoke is actually light gray and that is most likely to be caused by a small amount of oil burning.

When does it smoke? If it smokes mostly on startup and then stops when it could be a worn valve guide or deteriorated valve guide seal (or possibly several) allowing a tiny amount of oil into one or more cylinders. Sometimes this looks like a smoke screen for a few seconds.

If it smokes mostly when you are cornering it could be too much oil in the crankcase. The oil should never be above the high mark on the sight glass or dipstick when the bike is on the centerstand on level ground.

Does it only happen after the bike has been parked outside and it is cool in the morning? If so it could just be steam from condensation inside the mufflers.

Without more information it would be impossible to diagnose.