2018 M8----Sumping? Failures?
Grand HDF Member
Joined: Jun 2007
Posts: 4,599
Likes: 421
From: Lansing mi
I'm one of the guys that love Harleys. But I do have a little fear of the M8. I feel more confident on a TC.I don;t know why but I cant find much of any thing on a Softail sumping. I don't get that. I do know this, I have went out of my way for 2 years now to ask every M8 owner I could about there M8,. Not a single one had a sumping problem.. I know 1 guy on here that did sump more then one time, I even talked to the dealer that took care of his last sumping so that one is real. I just don't get it.. So I just call my self confused.
Member
Joined: Jul 2009
Posts: 4,310
Likes: 1,079
I agree with this fully, and have stated it from the onset. It has been long known that there have been out-of-round reports on the factory cylinders, and also the Screamin' Eagle cylinders. There has to be a direct connection there.
I have never seen a report of sumping from owners with aftermarket stage kits like mine. Never. I measured the cylinders and the pistons prior to installing them and everything was perfect. Zero oil consumption and good ring seal. I'm convinced that this has been the root cause of the issue. HD, it would seem, has made this determination also since they have incorporated the seal on the scavenging pump. It's no coincidence.
I have never seen a report of sumping from owners with aftermarket stage kits like mine. Never. I measured the cylinders and the pistons prior to installing them and everything was perfect. Zero oil consumption and good ring seal. I'm convinced that this has been the root cause of the issue. HD, it would seem, has made this determination also since they have incorporated the seal on the scavenging pump. It's no coincidence.
HD overnighted the custom cylinders/pistons and the dealership made the installation on my bike a priority. They had the cylinders/pistons installed in a day and heat-cycled for me to take the following day.
I was able to get about 500 miles before this stage IV 117 M8 engine with lab-matched cylinders/pistons sumped. That’s when HD authorized the factory built Stage IV 117 engine (#4 engine) to be built and shipped to my dealer for installation.
That experience ended my belief that out-of-round cylinders had anything whatsoever to do with sumping, at least with my M8 engine.
Last edited by Heatwave; Jan 29, 2019 at 08:00 PM.
Seasoned HDF Member
Joined: Jun 2015
Posts: 8,055
Likes: 8,080
From: Canada
FYI, I thought the same as you for awhile. It just had to be out of round cylinders. When my 3rd engine sumped, HD offered to have so-called lab specced and matched cylinders and pistons machined for my bike. They were confident the custom cylinders and pistons would resolve the sumping.
HD overnighted the custom cylinders/pistons and the dealership made the installation on my bike a priority. They had the cylinders/pistons installed in a day and heat-cycled for me to take the following day.
I was able to get about 500 miles before this stage IV 117 M8 engine with lab-matched cylinders/pistons sumped. Thats when HD authorized the factory built Stage IV 117 engine (#4 engine) to be built and shipped to my dealer for installation.
That experience ended my belief that out-of-round cylinders had anything whatsoever to do with sumping, at least with my M8 engine.
Member
Joined: Jul 2009
Posts: 4,310
Likes: 1,079
Im not saying anything. Im sharing what HD Technical services told me and what my dealer told me. If you have an issue with what they told me, then your issue is with HD.
Road Warrior
Joined: Jul 2012
Posts: 1,996
Likes: 417
From: Cranbourne, VIC Australia
No disrespect to Australia (having had multiple business trips and vacations in your beautiful country), but the experience of sumping in such a small market as Australia is hardly a good sample. Australians bought a piddling 3600 Harleys of ALL models for the first half of 2018. That's maybe a total of 5000 M8s sold in 2018. And those Aussie sales were down a crushing 18% from 2017. http://www.mcnews.com.au/motorcycle-...-q2-australia/
But as I recall, your source also projected a single digit sumping failure rate which would still have thousands of HD customers worldwide experiencing sumping M8 engines (more than every Australian that bought a Harley in 2018). For someone bored with monologues about sumping engines.... why the hell are you follow a thread titled "2018 M8----Sumping? Failures?"
But as I recall, your source also projected a single digit sumping failure rate which would still have thousands of HD customers worldwide experiencing sumping M8 engines (more than every Australian that bought a Harley in 2018). For someone bored with monologues about sumping engines.... why the hell are you follow a thread titled "2018 M8----Sumping? Failures?"
Road Warrior
Joined: Jul 2012
Posts: 1,996
Likes: 417
From: Cranbourne, VIC Australia
Well to be honest, I have never had to replace an engine in a $44K car, but I have had to replace many engines in $90K+ cars (mine, my families or customers), does that count? Is it ideal, nope. Does it make me super happy, not particularly. But as long as the manufacturer is sorting out the issue under warranty, and providing a comparable loaner in the mean time, what else can you ask for? Nothing mechanical is 100% reliable or unfaultable, especially new designs. Does crying from the rooftop about your issues, touting the doom and gloom everyone else faces make you feel better about the issue?
Outstanding HDF Member
Joined: Oct 2009
Posts: 2,791
Likes: 690
From: Smalltown,USA
It's not just a HD problem .Go on a Jeep Forum and read about the new jeeps having frame weld issues. They can cost from $29 to $50 grand new. Anything mass produced is gonna have quality problems. Jeep will do a case by case issue just like Hd is doing.
Seasoned HDF Member
Joined: Jun 2015
Posts: 8,055
Likes: 8,080
From: Canada
Actually you said that ended your belief that out of round cylinders was the problem implying that if the lab did them then that assured they were round. I have no issue with HD and Im not an M8 owner, this site stopped me from considering one so I bought a 66 instead.
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Seasoned HDF Member
Joined: Dec 2005
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From: poway
The cylinders need to be seasoned or from a different source. Also break-in has a lot to do with ring seal. (and we're back to the operator)
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