Milwaukee Eight (M8) 2017 and up M8 Air and Liquid Cooled discussion
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View Poll Results: Do you have a sumping problem
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15
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No
67
70.53%
I don't know
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Old Sep 27, 2017 | 11:42 AM
  #11  
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If you do a google search you see lots of sumping issue reports on bikes of all years and all makes/models...from what I am reading it looks like most of the people reporting issues have stage and performance upgrades and ride it like they stole it.

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Old Sep 27, 2017 | 04:47 PM
  #12  
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Originally Posted by flashracer
What exactly is it?
That's what I'm asking?? LOL.
 
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Old Sep 27, 2017 | 04:52 PM
  #13  
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Originally Posted by MiniWolf
If you do a google search you see lots of sumping issue reports on bikes of all years and all makes/models...from what I am reading it looks like most of the people reporting issues have stage and performance upgrades and ride it like they stole it.

Screen Grab

Thank you. This exactly why I'm choosing to keep my bike the way it is. I've done mods to past bikes and they never ran as good as when they came from the factory. I'm not looking to race on a track. Just want to feel the wind.
 
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Old Sep 30, 2017 | 05:25 PM
  #14  
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I have a stock 17 CVO StreetGlide w/ a little over 3,000 miles and it's sumping.
Only mod is Rinehart slim lines w/ 4.5" mufflers.
It started a long time ago but has gotten to be more frequent.
When it starts, I get terrible fuel mileage and when you throttle down the engine brakes like crazy.
Maybe I should be running Diesel fuel and it's really a Jake Brake? LOL
 
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Old Sep 30, 2017 | 07:57 PM
  #15  
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Originally Posted by Bob Coco
I have a stock 17 CVO StreetGlide w/ a little over 3,000 miles and it's sumping.
Only mod is Rinehart slim lines w/ 4.5" mufflers.
It started a long time ago but has gotten to be more frequent.
When it starts, I get terrible fuel mileage and when you throttle down the engine brakes like crazy.
Maybe I should be running Diesel fuel and it's really a Jake Brake? LOL
Seriously? That sucks and a CVO too? Wtf?
 
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Old Oct 1, 2017 | 05:54 AM
  #16  
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Never heard the term myself so that makes only two of us who don't know! Worked on a good number of Harley engines though so from the info on this thread I imagine that through insufficient oil extraction from the mostly dry crankcase. Not the oil sump!
I imagine that if it fills to above the lower part of the crankshaft and bigend there would be a lot of splashing and frothing and excessive crankcase pressure.Yes there would be a power loss but what other symptoms tell you that it is sumping? A lot of presumping methinks?
 
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Old Oct 1, 2017 | 07:04 AM
  #17  
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Originally Posted by Bob Coco
I have a stock 17 CVO StreetGlide w/ a little over 3,000 miles and it's sumping.
Only mod is Rinehart slim lines w/ 4.5" mufflers.
It started a long time ago but has gotten to be more frequent.
When it starts, I get terrible fuel mileage and when you throttle down the engine brakes like crazy.
Maybe I should be running Diesel fuel and it's really a Jake Brake? LOL
I wondered if this issue affected stock setups. I was getting the impression that it was an issue for a stage2 and above setup. although, isn't a cvo technically a stage 2 out the box?
 
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Old Oct 1, 2017 | 08:34 AM
  #18  
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Don't know why that would be?Stage 2 is inlet exhaust and cam change Stage 3 adds cylinders and Pistons so nothing to do with crankcase or oil pump which seems to be the focus. I will check with our Master Tech tomorrow.
 
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Old Oct 1, 2017 | 04:06 PM
  #19  
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ALL M8 variants can and have sumped. I've personally had a 2017 stage 2 and stage 3 sump. My current 2018 POS stage 1 with a new pump is sumping as well. There's been so many generations of pumps Harley is throwing at this problem I don't think anyone outside of the MOCO knows what the latest one is. IMHO they have a serious design flaw that they're trying to find a fix for with a field replaceable part.
 
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Old Oct 1, 2017 | 07:10 PM
  #20  
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How do you know if it's sumping?
 
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