2018 M8----Sumping? Failures?
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Probably because you haven't been around long enough.. Early TCs had issue. It was determined to be the result of bad oil pump alignment and possibly the material used for the inner pump O ring.. Baggers so has a known issue of spitting out the dipstick and oil all over the place which I suspect is the reason why they now screw in.. HD changed air vent line from the tank to the motor to fix this.. In 99-2000 this place didn't exist. There was a news ground and another group on Yahoo.. Maybe 1 or 2 others. They also has rear cam bearings self destruct, When they went, the motor would sump from the scavenge rotor being destroyed. HD added a 5 year/5000 mile warranty (IIRC) on the cam bearing failure.
I have to respectfully disagree. You can search the largest forum on HDF (Touring) which is primarily about Twin Cams for over a decade and there are almost no reports of sumping in a factory TC engine or a TC upgraded with only HD parts. Sumping was simply NOT a significant drivetrain defect in a factory Twin Cam engine (or one that was upgraded with all Harley components).
Yes the Twin Cam had other weak points such as lifters, crank and cam bearings but even early TCs (I owned a 2003 TC bought new in September 2002) did not have significant reports of stock engines catastrophically failing from sumping. If you made upgrades on a TC with non-harley components, or improperly installed the oil pump, you were at greater risk of sumping (and other failure points) but not with factory components that were properly installed.
If you believe otherwise I would welcome reading a TSB or an actual report of sumping in a factory TC.
Last edited by Heatwave; Jan 18, 2019 at 10:04 AM.
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From: Md
Hey Heatwave, hows your 2019 engine in regards to sumping. I havent sumped in my 18 since my latest new engine but I also dont speed shift anymore between 4-4500 rpms, I have the feuling race pump but without testing it riding hard short shifting I wont ever know if it helped. So I ride but not like Id like too. Cant afford a $12k repair and losing the bike for another 2 month fix. Warranty was voided because of PV tune. Dean
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Hey Heatwave, hows your 2019 engine in regards to sumping. I haven’t sumped in my 18 since my latest new engine but I also don’t speed shift anymore between 4-4500 rpms, I have the feuling race pump but without testing it riding hard short shifting I won’t ever know if it helped. So I ride but not like I’d like too. Can’t afford a $12k repair and losing the bike for another 2 month fix. Warranty was voided because of PV tune. Dean
I would just enjoy your bike and not worry about it. There's not much more you can do about it anyways if you're out of warranty. Hopefully the Feuling pump gives you a margin of safety to avoid sumping, if you think you're at risk.
My recommendation would be to check the oil a little more frequently before and after a ride. It doesn't take much effort and it'll be an early indicator if you have an issue. If your oil is significantly lower after a ride than before you started, you might have an issue but if the oil level remains unchanged after a good days ride, you have nothing to be concerned with.
Last edited by Heatwave; Jan 18, 2019 at 10:05 AM.
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From: poway
Uhhhhh been "around" riding motorcycles for almost 50 years. I've owned numerous TCs and still currently own one. I've been a member of HD Forums since 2009 under the current name and was on HDforums and other forums under a different name for almost a decade before that. There was never a TSB for sumping in factory TCs that I'm aware of.
I have to respectfully disagree. You can search the largest forum on HDF (Touring) which is primarily about Twin Cams for over a decade and there are almost no reports of sumping in a factory TC engine or a TC upgraded with only HD parts. Sumping was simply NOT a significant drivetrain defect in a factory Twin Cam engine (or one that was upgraded with all Harley components).
Yes the Twin Cam had other weak points such as lifters, crank and cam bearings but even early TCs (I owned a 2003 TC bought new in September 2002) did not have significant reports of stock engines catastrophically failing from sumping. If you made upgrades on a TC with non-harley components, or improperly installed the oil pump, you were at greater risk of sumping (and other failure points) but not with factory components that were properly installed.
If you believe otherwise I would welcome reading a TSB or an actual report of sumping in a factory TC.
I have to respectfully disagree. You can search the largest forum on HDF (Touring) which is primarily about Twin Cams for over a decade and there are almost no reports of sumping in a factory TC engine or a TC upgraded with only HD parts. Sumping was simply NOT a significant drivetrain defect in a factory Twin Cam engine (or one that was upgraded with all Harley components).
Yes the Twin Cam had other weak points such as lifters, crank and cam bearings but even early TCs (I owned a 2003 TC bought new in September 2002) did not have significant reports of stock engines catastrophically failing from sumping. If you made upgrades on a TC with non-harley components, or improperly installed the oil pump, you were at greater risk of sumping (and other failure points) but not with factory components that were properly installed.
If you believe otherwise I would welcome reading a TSB or an actual report of sumping in a factory TC.
BTW 99-2000 most forms didn't exist. They were mostly news groups..
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Wasn't the debut of the Twin Cam delayed a year because the sumping issue was discovered during pre-production testing?
I need to search for my reference, but my old, feeble mind seems to remember reading, many years ago, about the development of the TC and pre-production sumping issues. As I recall, they did a redesign of something in the case to aid in scavenging, and then released the engine. I didn't know that some sumping still occurred after the TC was put in production.... I thought they caught the cause and corrected it pre-production.
Does anyone else remember that or did I just dream it....???
I need to search for my reference, but my old, feeble mind seems to remember reading, many years ago, about the development of the TC and pre-production sumping issues. As I recall, they did a redesign of something in the case to aid in scavenging, and then released the engine. I didn't know that some sumping still occurred after the TC was put in production.... I thought they caught the cause and corrected it pre-production.
Does anyone else remember that or did I just dream it....???
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So you came in in 2003 after most of the stuff was fixed.. Like I said this is was early TC.. FWIW, Doing an HP up grade on 03s would blow the left side bearing, there was a TSB where they changed the torque procedure on the crank for that one. Not sure if I still have the TSBs, To lazy to go looking.
BTW 99-2000 most forms didn't exist. They were mostly news groups..
BTW 99-2000 most forms didn't exist. They were mostly news groups..
No need to dig it up. I'm familiar with it. But you're comparing apples and oranges. If sumping is a result of a defective bearing or other defective component as you are suggesting in the 1999/2000 TC's then I don't fault HD that much. Defects in manufacturing happen. But they can be identified and corrected.
The current M8 issue is a defect of engine DESIGN, not of manufactured components, otherwise we wouldn't still be seeing M8 sumping with 2019 engines. The latest and greatest that Harley had to offer with the M8 has resulted in many guys.... after 3 years.... still having to deal with the nightmare of a failed engine. The "lucky" majority have no idea how frustrating and demoralizing it is to deal with a brand new bike having a failed engine, let alone multiple failed engines. Just be thankful you aren't one of them.
But more importantly you are making a pretty sad case for Harley. Essentially you're saying that because bikes from 20 years ago had oil sumping, we shouldn't be surprised that today's Harley's also sump. If that's your point, then Harley's days are truly numbered.
Last edited by Heatwave; Jan 18, 2019 at 06:04 PM.
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Wasn't the debut of the Twin Cam delayed a year because the sumping issue was discovered during pre-production testing?
I need to search for my reference, but my old, feeble mind seems to remember reading, many years ago, about the development of the TC and pre-production sumping issues. As I recall, they did a redesign of something in the case to aid in scavenging, and then released the engine. I didn't know that some sumping still occurred after the TC was put in production.... I thought they caught the cause and corrected it pre-production.
Does anyone else remember that or did I just dream it....???
I need to search for my reference, but my old, feeble mind seems to remember reading, many years ago, about the development of the TC and pre-production sumping issues. As I recall, they did a redesign of something in the case to aid in scavenging, and then released the engine. I didn't know that some sumping still occurred after the TC was put in production.... I thought they caught the cause and corrected it pre-production.
Does anyone else remember that or did I just dream it....???
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Joined: Jan 2006
Posts: 11,476
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From: Charleston, SC
Interestingly enough, the design issue with the prototype TC was oil filling the cam chest which was cured by sealing it off from the flywheel case and reducing the size of the scavenge inlet which is the same stuff they are attempting once more on the M8.
Last edited by lp; Jan 18, 2019 at 07:58 PM.
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From: North of Hell, South of Heaven
I was pooh-poohing the sumping issue as being very limited - that is until a buddy of mine told me this afternoon that he and two others of his group are experiencing some overheating and momentary loss of power. 
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