To the OP...

I think you are correct in your presumption that sumping is not an "all or nothing" event.

I experienced a range of sumping scenarios before my bike was finally repaired under warranty. On three occasions I had major sumping events with in excess of 30 ounces of oil in the crankcase. These events were easily discernible as the performance degradation was very obvious.

But I also had other less significant sumping events where I observed 10-14 ounces of oil in the crankcase. These events were only known because I drained the crankcase - I couldn't feel any associated performance issue. I also observed slight variations of the dipstick oil level (1, 2, or 3 hash marks) similar to what you have described.

Even after the warranty repair (with the latest 8-lobe pump) I still see minor variations of the dipstick oil level, but have not experienced what I would consider a significant sumping event. That indicates to me that my bike is still sumping, at times, to some extent, but not to the extent that I can feel a performance hit.

Personally, based on my experience, I wouldn’t concern myself with dipstick oil level discrepancies of a few hash marks. You can drive yourself crazy trying to chase them down – I know!

Now if your dipstick level is varying by a half quart or more, that would certainly get my attention. I think you need at least that much oil (half quart) in the crankcase before you begin to feel a performance hit.

As for SB1450, I think the way it is written can certainly mask a sumping condition, as letting the engine idle for 45-60 seconds will in most cases scavenge some of the oil from the crankcase, thereby skewing the amount of oil measured when draining the crankcase. To get a real handle on the amount of oil in the crankcase during operation, my postion is that the crankcase should be drained immediately after operating the bike at speed bike, without the 45-60 second “idle” buffer.

And finally, if you are hoping for a warranty repair… Good luck. It took me multiple attempts at the dealership before they confirmed the sumping issue, even though I had confirmed it myself, and documented my findings, several times over a 400-mile period. If you can’t get to the dealer during a major sumping event and have them diagnose it immediately, there’s a good chance that they may never replicate the issue. SB1450 as written, is destined to provide many false negatives.

 

Minor variations on the dip stick can be attributed to where you park when you check your oil. I have a spot in my garage where I always park to check my oil, the same spot where I fill it when changing it. It will always read full in that spot. If I check it on the other side of the garage it will read about 3 hash marks down, move to my spot and it's full again. I very seldom check it hot anymore, as long as it's midway up on the stick when cold I am good. 2018 Heritage 114, approx 12,000 miles and never had an oil issue.

 

I do the same... Anytime I want a precise check I do it in the same spot of my garage... And always cold. 3 hash marks down from full on the dipstick is my baseline. I've determined that level to be same as full hot.

If and when I check the oil while riding and hot, I always take into consideration the ground level and oil temperature.