Forgive me I'm new to this forum. I originally posted this to general but I think it belongs here...

Harley will be replacing my M8 117 motor on my new 2018 CVO Street Glide in a couple weeks and I'll need to go through the grueling 800 km break in period all over again. Arghhh! When my stock M8 117 motor sumped and catastrophically failed at 1200 kms there was no pre hand warning. I was travelling at highway speed in 4th gear at around 4500 rpm and I didn't hear any strange sounds prior to it cutting out, the motor just simply stopped and all I was left with was the 900W stereo system still blaring and 2 lanes of traffic now to cross without getting creamed. I safely rolled the bike to the side of the road and when the bike came to a stop I could instantly smell burnt oil. I didn't experience any kind of power loss at the time but I'm thinking maybe it was always a little sluggish right from the start? This was my first bagger and obviously it was also my first M8 117 so I had nothing else to compare the power with except to my 110 Dyna Low Rider S which there was no comparison, the Low Rider S was much quicker but also 300 pounds lighter so I kind of expected that. Thinking back the engine always ran super hot on the right side, maybe it was a dud right from the factory? I'm curious if I hadn't been listening to the stereo if I would have heard some kind of pre warning sign??? What does a motor sounds like when it's sumping?

 

Stopped while driving and you were forced to avoid traffic to get to safety! In the USA we'd contact the NHTSA (https://www-odi.nhtsa.dot.gov/VehicleComplaint/). In Canada you should contact this agency and report the serious safety defect: http://www.tc.gc.ca/eng/motorvehicle...-vehicles.html

It might save another riders life.

 

More of a an instant feel of loss of power. Engine straining. Requires increased throttle input to maintain speed. After a while it gets hot and then ultimately can smell and smoke. If the rider is in tune with the bike you may be able to catch it before damage if you know the signs.

I would advise anyone to avoid use of cruise control if you suspect sumping. There are a lot of CVO 117s exhibiting this issue and there is no indication Harley has a fix. My 120" did it once and I knew immediately and shut it down.

Take one of these with you - could keep you from having to call a tow truck next time it happens. Even though the below mentioned kit is in jest, I seriously did carry this with me until I installed the Feuling pump and plate.

https://www.hdforums.com/forum/milwa...mping-kit.html

 

 

I have no first hand experience thankfully,but I know some have reported lots of heat and a burned oil smell along with the loss of power. I'm afraid that it's just too late once you have the loss of power. At 4500 RPM's cruising in 4th and 3 quarts of oil in the sump there is nothing left to lubricate the engine, at this time the oil pump also sucking air and incapable of pumping oil.
Do you always cruise at such a high RPM?

 

 

^^
Yeah 4500 on the highway in 4th does sound a bit high if cruising. I could see acceleration to get there of course.

 

Another thing I want to bring up for consideration...

I don't think any of these sumping situations comes on instantly; I think it develops over some time. That is, I think there is an already too high amount of oil in the sump on many of these bikes to begin with at even "normal/light use" applications. When pushed harder, especially with larger displacements, even more oil accumulates in the sump and then its on.

I do believe in some cases its possible to avoid engine damage if shutdown quick enough; that was the case with me. I sumped once then pulled 2 quarts out of the CPS hole. I borescoped, compression tested, leakdown tested and all was fine. Disassembly of the camchest to install the Feuling race kit showed know signs of wear to cams, lifters nor even the stock oil pump.

 

I only took the bike above 4000 after the break in period but yeah I like to ride between 3500 and 4500. I was told that the new 117's like to be ridden in the higher RPM range and that the peak horsepower is 92 at 4500 RPM.

 

I would target cruise at 3000-3500. Plenty of torque at 3500. If accelerating, by all means let it rip. But cruising at 4500 for miles is way too high.