Look for leaks

 

Does it do it "when getting into the throttle" or just "when getting out of the throttle"?

 

Check the trans shift shaft seal. Very common and stinks when hot.

 

It's being burnt through the motor. when you get out of the throttle it's pulling oil into the motor and being burnt in the combustion chambers and the air draft is pulling it from the exhaust and back into the riders area and stinks like burnt oil, which it is. if you let up on the throttle gradually you don't smell a thing, it's just when pass a car or are doing like 90 and close the throttle quickly it pulls the oil into the motor.
Jonnierock

 

Very common on older bikes with higher mileage...and higher mileage not necessarily meaning 'high mileage'...I've noticed this a lot when riding with guys that have forty, fifty thousand miles or more on their bikes.


Simple explanation. When you're 'getting out of the throttle', or decelerating, if you had a vacuum gauge hooked up to the intake manifold, you'd notice high vacuum. Once the engine starts wearing significantly, minute amounts of oil will seep by valve seals and piston rings. That translates into hot oil into the exhaust, and voila! Stinky!

Usual cure would be a top end rebuild, but why bother? If you aren't using much oil, it's no biggie!

 

I agree with Johnnie, how many miles on the bike? can be bad valve guide seals allowing the oil to go back into the combustion chamber due to high vacuum. Doing valve guide seals may be a big help, but if mileage is high, a valve job may be in the mix, and check to see if cylinder leakage is enough to warrant a full top end job. the bike is a bit old, and sounds due for such a repair

 

Check/replace the umbrella valves inside the rocker boxes. if that isn't it, one of the valve guides may be cracked.

 

Unless it gets like this, I would not worry about it.

 

That is the best explanation of your issue. I have a freind with that problem on his sporty. The fix is to vent the engine to the atmosphere instead, there are several aftermarket ways to do this,, here's a simple video of one way.


It'll still blow the oil, but it won't be routed into the engine to burn.