What I am getting at is risk without reward.

In other words risking voiding the warranty to fix sumping by installing an oil pump that does not have a 100% cure rate.

I am not sure, but I thought I read about sumping even with the fueling oil pump.

Others have pointed out that it is not really the oil pump even though a poorly designed or manufactured oil pump would be the first thing that comes to mind with this sumping issue.

It would be different if installing an aftermarket oil pump would void the warranty but would be a 100% guaranteed fix for the sumping.

Of all the potential teething problems the M8 could have had, simple oil circulation was the least expected potential problem. I kind of thought it would have been the valve train or other unique aspect of the engine.

 

yeah, I think it's way premature to jump to aftermarket oil pump. the problem will be discovered or Harley sales will dive even more than they already have.

 

You're not being contrarian; we ALL believe that it SHOULD be able to do so.

The question is whether it can, and what we have to do to avoid being stranded. Harley can, should, and must continue working on this and they must provide a fix that works for everyone. But in the meantime, we at least now have a reasonably workable theory on what causes it, and perhaps a simple cool-down interval can avoid catastrophic engine damage.

I would like to run some tests to see how quickly the oil accumulates under freeway conditions, but I don't know how valuable my testing would be, as I've logged 4,000 miles with no hint of sumping yet, so I don't know that I'm a sumper or that my bike is a potential sumper.

Maybe Keithhu is our best resource for this -- if a bike driven at a constant 75mph can sump, the question becomes -- how long was that bike driven at 75mph? If net oil accumulation is happening at 75mph conditions, then sumping would be inevitable if driven long enough. The question is how long do we get before an idle-down is necessary to clear the accumulated oil?

 

Exactly. If this theory of continuous oil accumulation is correct, it's possible that a sufficiently over-capacity scavenging pump could prevent that accumulation. Now, theoretically Harley's pump should have been designed with sufficient capacity, so my speculation goes along the lines of others like Steve who say that it's not the pump itself that's the problem, I think the root problem is probably blowby, excessive leakdown, perhaps acoustic currents caused by the pressure of the cylinders moving, and oil flinging and all the other things that have been discussed. And a new pump wouldn't fix any of that. But, the net RESULT is that oil ends up excessively accumulating in the crankcase. Regardless of why it accumulates, it clearly does. And a pump with significantly more scavenging capability could theoretically clear that oil out before too much accumulates and sumping happens. Perhaps.

In effect, it's like a pan of water on a hot stove. The hot stove WILL cause the pan of water to boil, sooner or later. If you throw enough ice cubes in the pan, you can delay that boiling time; with enough ice, you could delay it forever. Even though the heat is still being added, the ice delays the onset of boiling. That's what I think an overly-scavenging pump would do; the underlying cause of oil accumulation would still be happening, but the excess scavenging capacity would be like ice cubes thrown in the water.

Whereas with the idle-down experiment, that's basically like taking the pan off the stove for a while. It sucks; you want to be able to leave the pan where it is, but -- if you do, it'll boil over. So you gotta cope with what the reality demands. The ultimate solution would be to turn the stove's temperature down so that the water never reaches the boiling point at all... that's the allegory to the fix that we hope Harley someday implements, so that excess oil does not accumulate at all. But we're going on nearly two years with no fix in sight as far as we know (unless Heatwave's new engine does incorporate some new case design or other fix that we don't know about yet). So, again, we gotta deal with the hand we're dealt.

 

Excellent points. Until we have a definitive identified cause for sumping, the aftermarket oil pump is a gamble because it could potentially be considered something that Harley might decide to void a warranty over, if they could prove that it was responsible for a failure or that it was somehow a "racing" part. It would be interesting to hear Fueling's or S&S's take on their pumps, if they consider them to be a cure for sumping and if they consider them to be qualified replacement parts or if they consider them to be racing parts. If they are qualified replacement parts, then theoretically M-M should prevent Harley from voiding a warranty just because a different pump was installed. But, without a definitive solution for sumping, I agree it remains a gamble.

 

While it always happened to me on the highway, generally there was 15-20 minutes of city riding leading up to it. If memory serves, all of it happened after about 20-30 minutes of highway riding.

But also understand that the first occurrence happened after riding to and from Sturgis from Michigan, I had 5600 on the bike when it first happened. And I would say both directions on I-90 between Rapid City and the Minnesota line (a few hours each direction), we were doing a constant 85-90, with zero issues. In September I was riding on the highway heading up north when it first happened. But after the first occurrence I only had about 300 miles on the bike the 2nd time it happened, and the last time, about 500 miles. Stock twin cooled 107 with slip ons only.

 

can't remember, has this been reported here on stock oil cooled 107's? they use a larger oil pump and oil cooler than twin cooled engines..curious if those configuration differences are significant on how the whole system operates/functions

 

No oil cooler on a twin cooled, its liquid cooled.

 

i know, I should have used a comma, followed by "and an oil pump", but same question applies

 

You need to read the warranty language in the back of your Owner's Manual. A non-Harley Davidson part does NOT have to contribute to a failure. The mere fact of installing any non-HD parts or non-epa approved parts on the drivetrain will result in the voiding of your HD factory Drivetrain warranty if HD has knowledge of the non-HD component. And if you bought an ESP, the ESP extended coverage will also be voided if the Factory warranty was voided. The language in your owner's manual is very clear. You can ask several on this forum that have lost their Factory Warranty for lesser reasons.