Originally Posted by murray
..The oil drains into the combustion chamber due to a open exhaust valve when the motor is off and the bike is on the side stand.......
But, but, sir, how would oil leak upwards into the combustion chamber?
...If the oil leaked past the rings you would have a major cloud of smoke with motor braking when you apply throttle...
The way I heard it explained years ago, a wee bit of oil will leak past the rings if the ring gap is at the bottom of the cylinder... when the piston stops. If the gap is anywhere else, little or no oil won't get past.
I don't think this will damage the cat since the oil is burning.
The cat is not yet heated up, and the oil is only there for a moment. Raw fuel, such as a 'missing' cylinder with no spark, will dump enough fuel into the Cat to cause damage.
Smoke on startup is 'normal' for the Brick engines, and has been a source of puzzlement, amusement, and mockery since the days of the K75.
Don't worry, just ride it.