I have owned brand new '77 and '81 GoldWings. They both would smoke (left side only) on start-up if parked on the sidestand, and they did it from day one out of the crate. Valve guide seals were NOT the problem, piston oil-ring design and the proximity of sump level to cylinder bores were the causes (ie: engineering).
Like sandiegobrass said, age & wear are now oftenadditional causes on the older 'Wings. Generally, oil smoke that seems worse while idling & starting out from stoplights, or during deceleration,might be valve seals mostly.Seemingly constant oil smoke while driving or accelerating would often be from worn rings. Of course, head gasket problems can skew a proper diagnosis at any time... :waving:
I replace my valve seals with new viton seals. My old seals were brittle. I replaces the seals but also included some other work.
My bike does not smoke on startup anymore unless it is started for very short bursts with the engine is cold from start to start. If the engine warms up to operating temps and then shut off, it will not smoke on the next startup. Before I changed my oil abunch of times and before I put valve seals on it, it would smoke very bad on every startup.
I was told I was wasting my time putting valve seals on it but at this time I am very glad I did. I really think it help in my situation. Hey for $29, I was willing to try it.
New valve stem seals worked for my GL1100 which would smoke for a few minutes at startup after a few days of non-use, then clear up. It wasn't a heavy smoker and had low miles (I think 26,000) so I was confident the seals were the problem and not piston rings at that low mileage.
The new seals worked and when I sold the Wing a few years later with 47,000 miles, it was still smoke-free.