Sweet coolant smell or for sure oil smell? Did you mean the breather reed valves under the cover? Have you verified that the oil return at the bottom of the chamber is open? Head gaskets can by symptomatic such as this as well.

Reed valves is right. Oil return open. Ran two hours yesterday at little over half throttle for hour then opened wot ran for hour before smoke. Motor sound like well tuned airplane smooth then smoke. I seem to notice sharp turns or hill may be involved. But does on smooth straight. Cleaned

From here if you are not experiencing any external case leaks (could be anything as simple as a missing dipstick seal) I expect the start of a head gasket leak. That is of course assuming that we know oil is oil and of correct weight. The level of the sump remains consistent?