Given all I've read about this, I would agree with what others have said, sumping seems to most prevalent on bikes with a combination of multiple factors coming together to make the perfect storm so to speak.

Very bad news for those that it happens to, but still a relatively rare occurrence in the total number of motors built. Which could also explain why some bikes sump multiple times while others never do.

On those bikes that have multiple contributing factors HD's fix, pump and back plate seal, may not be enough to stop it from reoccuring. While on those bikes that have sumped due only to the seemingly biggest cause, the oil pump and no seal, changing the pump out and adding the seal on the back plate may prevent it from happening more than once.

I have to wonder if HD has set up a lab with multiple motors in it on which they're trying to create sumping in them through various means and combinations.

 

i definitely have pressure build up,and it doesnt take long,brand new stock engine,just changed break in oil,i am being told this is normal.When my vent gets here im going to put a 10 lb gauge on it ad see what it reads,took video with phone,can send text with video but cant get it to load on site

 

Does anyone else think this entire thread is madness? Its 2019 and does anyone think that customers should need to re-engineer the mechanical operation of any brand new modern engine sold in the US market? Paticularly one like the M8 that supposedly had a million test miles on it before it was launched?

Sheer madness that anyone should have to consider jury rigging the venting of a brand new internal combustion engine in 2019. Makes no sense that so many find this acceptable. NEWSFLASH....... ITS NOT!

 

This is a case of one or two riders having a particular symptom with their bikes, and looking for comparison information.

We understand that your passion is to over-magnify the size of a gnat.

Harley owners are unique among motorcyclists because they love to tinker and "re-engineer." Riders of Japanese bikes tend to have far fewer issues to tinker with, and are fairly bored with their boring motorcycles that never break and don't need tinkering.

You might be happier with a Honda.

 

Lol. 1 or 2? Really?? My passion is to ride and own reliable, powerful and functional motorcycles. My passion is NOT to re- engineer the basic design of a brand new engine so it functions properly. That’s what I paid the manufacturer to do in the first place.

 

I am curious if anyone on the forum has tried the T-MAN vent that mounts at the dipstick position?

 

I installed the M3 vent on mine tonight. I did cut the hose and put the filter by the ABS module instead of just laying it on the engine.

 

I don't understand why everyone is wanting to do this until someone shows a bike sumping on the dyno, then put the vented cap on and bam, no more sumping.
Seems everyone is putting the cart before the horse !

 

Sorry, I am missing something. Who's bike sumped on the dyno? And your saying they installed a vented cap and it didn't do it anymore?

 

Rin Tin, I'm asking a question as well. I do not understand why everyone is jumping on the venting bandwagon through the dip stick area when it's not proven to help sumping as some have stated. Yes a bike can sump on a dyno but that's what I'm asking. Whats the proof that the venting will help prevent sumping ?