Oil in my exhaust

[MikeyVeitch]

So I have just finished my bandit rebuild with a 1127 motor. I started it up for a test run before I put all the body work back together and when admiring my new pie cut exhaust, I noticed that it had a bit (a lot) of oil. Thinking back to when I had changed the sump, the engine was sat basically upside-down for a couple of days. My question is, would this have caused oil to leak into the cylinders? I don’t think that it is stem seals, gaskets or anything of that nature because I have found oil in all 4 downpipes and the engine id from another bike of mine that is no longer on the road and it ran perfectly, low mileage, never skipped a beat. 
Any reply’s would be heatedly appreciated. 

[DAZ]

Yes quite possible if it's been upside down for oil to permeate past the pistons  and rings ,the rings actually only seal properly when the engine is running,combustion gasses push down past the piston crown,into the ring lands and push the rings out towards the cylinder wall to create a better seal 

If it were mine and I knew it had no issues previously I would run it making sure it sounded good till it was good and hot once I'd cleaned the oil off the exhaust system,don't want it burning on  

Edited March 2, 2023 by DAZ
Addition

[TonyGee]

if it is because it was upside down it'll eventually burn off. 

[Swiss Toni]

It couldn’t have leaked a significant amount of oil past the rings. If it had, you might have a bent rod on your hands! 

[DAZ]

10 minutes ago, Swiss Toni said:

It couldn’t have leaked a significant amount of oil past the rings. If it had, you might have a bent rod on your hands! 

The amount sounds relatively small,if you think you've only got a few thou piston to wall clearance,then it's got to get past the three sets of rings,again it's thousands of an inch gaps, its not going to hydrolock like a leaky fuel tap and float valve would after a week or two.... But any fluid looks worse than it probably is think of how far a pot of tea goes if you knock one over , just my opinion 

[Swiss Toni]

Yes Daz, you’re probably right. If there had been a good amount of oil in the combustion chamber, it probably wouldn’t have fired up. As for hydraulic lock … got the tee-shirt!