Hi I am considering getting into a slightly used 2017 RGU. There are a few long threads on the sumping issue and for those of us late to the party I am wondering:
What is sumping? How would I know it's happening?
Is it only an issue with Stage 3/4 builds or is it also an issue with stock engines?
Is it an equal issue whether 2017 or 2018 model, or does a different oil pump or some such fix the issue on 2018's?
I realize many will tell me to do the research but the main thread on this issue has over 1000 posts and I think many of us could benefit from a recap. Thank you.

 

If you really are looking for sumpfing to worry about you should read all the threads you can find.You won't find an answer or be able to predetermine whether your target bike will sump!Sumpfing is happening as these threads are dying off.
Best news is the more trouble free mileage it has done the less likely it is to occur.
If you really want a great bike just buy it and enjoy the ride!

 

Our bikes oiling system is a dry sump system. Meaning oil is not supposed to collect in the crank case. It is pumped out into the oil pain.

Sumping occurs when oil collects in the crank case, causing increased pressure in the crank case, and starvation of oil to other parts of the engine.

Symptoms include sudden inability to accelerate (bike bogs down when you try to accelerate), smoke coming out of your mufflers, and noisy clatter from the engine because necessary oil is not present where its needed.

There is some speculation that it can be happening over short periods of time, but idling will allow the oil pumps to "catch up", thus making it difficult to detect until it becomes catastrophic.

So its like pancreatic cancer - once you notice symptoms, you're essentially too late, the engine is hosed.

Originally thought to be occurring only in stage III and IV M8 bikes, there have been many cases of it happening on stock 107 M8s.

Like mine. Harley has replaced my engine twice under warranty. The 2nd engine only lasted 300 miles.

 

Most are from tin men who sale other bikes. Read them. Most really do not even know how much oil really runs in the sump. And Harley sure does not publish it. Lot depends on year. My old 2004 has a lip in the sump that keep almost 24 Oz's or so in the sump and cam galley for inner cam bearing lubrication.

 

Wow! How do you know that?

 

Your best bet is not reading all these threads. Talk to a trusted technician. I am sorry but the internet is not the place to get reliable information.

 

So the way your 2004 is designed is why it is not happening to new bikes? Really?

You are an idiot!

 

From what read most sumping issues with the newer models happen when you do the stage up dates 3 and 4 is when this happen stock bike are pretty good.

 

Would free flowing exhaust and Intakes contribute to "sumping"? Wouldn't it have to? More air coming through the motor, changing internal pressures thereby upsetting harley's perceived "balance" within the motor?