Fair assessment as I acknowledged its just a gut estimate. The only “facts” I have are the same ones available to everyone. Not so sure about your HDF membership #s as it relates to the M8 bikes. My guess is that M8s represent less than 1% of all the Harleys on the road. If 1% of the HDF members own an M8, thats about 3400 M8 HDF bike owners, which sounds about right to me.

if 5% of the HDF members that own an M8 have experienced sumping or fluid transfer, you get 170 members dealing wih these issues. Pretty darm close to your calculation of 200. I stand by my gut estimate but I’m certainly open to more facts either confirming or suggesting a different failure rate for the M8 bikes.

Sorry if the below has already been posted but Matt Laidlaw mentions in the vid below he’s seen 3 or 4 bikes w/ these issues, in the video his employee burns down an M8 SG, never mentions “sumping” only that it was an oil pump issue but sumping is what it sounds like, new motor was needed.

“Andrews Milwaukee-Eight Street Glide: The Good, The Bad, The Ugly.”
30 min vid, can Skip to 15:00 min in:
https://youtu.be/b41JP-vfDYo

For the parade lap guys that will surely come here & say that’s not what a HD is designed for, F that, it’s exactly how I’ve been riding all my HD’s for over 30 years. If the M8 is not designed for speeds over 100mph the MoCo should come out and say so,,,,,, so I don’t have to look forward to a repair in the 2019 bikes & will keep it moving as my 93 Softail, 04 CVO & 16 CVO SG all handle that kind of riding all day long.

I know there are some that think the internet is blowing these issues out of proportion but I’ve been buying new bikes & cars for a long time, often frequent forums but honestly can’t remember another model/engine where new engines are being blown like this so frequently or after 2 model years the manufacturer issued numerous revisions to a part they claim is causing engines to fail but STILL hasn’t developed a fix for such a major issue. I mean you find issues in some new motors but can’t recall anything even remotely similar to this situation with M8’s & sumping.

Think that is another reason sumping gets so much attention; it’s not fully understood why it happens, there’s nothing you can do to prevent it, can happen just cruising or while riding aggressive, can happen to any tourer, stock or modded & ends in catastrophic results without confidence from the consumer that the issue is taken care of even after repair,,,,well because there is no oem proven repair. And people are afraid to go aftermarket say for an S&S or Fueling pump for fear of losing a warranty & still blowing a motor.

The dealerships & their employees are going to down play the issues, the net will make it seem more prolific, the truth is probably somewhere in the middle but I dont buy that transfer & sumping issues only affect 1% of bikes either, between the 2 issues I would guess it’s closer to 10%, half of which probably aren’t even aware they have fluid transfer. But that other Harley mechanics opinion, implying it’s the customers fault because M8’s have different capacities & customers are overfilling their primary is unfortunately part of the S.O.P. blame game at many dealerships.

The forum mantra “that’s what warranties are for” is laughable, especially since there is no proof that the repairs on stumpers are even fixing the problem/s. You shouldn’t have to worry about constantly checking fluids w/ every fill up or blowing up new engines, warranties are for the unforeseen & unexpected, you buy new EXPECTING for the most part you might have some small issues here & there to repair under warranty not for the dealer & MoCo pretending to repair an ongoing catastrophic blown engine problem & drain the consumer of confidence in their expensive machines, to say nothing of the reduced resale values on these affected bikes, does the warranty cover that too?

There’s no way the MoCo wasn’t aware of these issues during testing, I bet there was just no way to delay launch. MoCo customers are extremely loyal & although sales are really soft, I can’t think of another reputable manufacturer where consumers are constantly burning down new engines & customers just say; “well that’s ok, as long as you’re nice to me & I have a warranty, this is just a minor problem/inconvenience w/ such a small # of bikes affected”,,,, loyal almost to a fault imo. Fix the fooking problem already or at least communicate w/ your loyal following/consumers about wtf is going on.