I figured I would start this thread for anyone dealing with an oil sumping issue related to the installation of a Stage 3 or 4 performance kit on a new M8 bike.

Here's my experience: Bought a new 2017 CVO Limited in Nov 2016. Rode it a 1000 miles home. Love the bike. Upgraded to Stage 3 in December. HD released stage 4 kit in late Jan 2017. I figured what the hell, I would have done the stage 4 in Dec had I known, so I upgraded the stage 3 with the larger injectors, CNC Ported heads, SE 515 cam and 64mm throttlebody.

The Stage 3 was a very strong upgrade over the stock bike. A little softer than I cared for below 2500rpms but above 2500 made up for it. I only had a couple hundred miles riding time on the Stage 3.

The Stage 4 was great across the entire rpm. I was very pleased with performance across entire rpm range.

I started getting miles on the build. (now at 5000 miles) At first everything was great but I noticed rising temps and decreasing performance the longer I rode the bike. More than an hour of riding and the fun would start "running out of the bike". It would get sluggish to the point that it couldn't get out of its own way. Like it was dragging an anchor. Let it sit overnight and the bike would be back to being a rocket....but only for an hour or so.

I took the bike to Laconia Bikeweek for a week of hard riding in the mountains. I also had another bike with me so I split the riding between the 2 bikes. One day I was riding the 2017 Stage 4 and it was incredibly powerful. Nice cool morning with 93 octane. It ripped through the mtn roads as I led a group of strong riders including a former motorcycle racer on a sport bike. Very hard running. (Separate note...bravo to HD on the suspension. SIGNIFICANT upgrade over my 2010 CVO Ultra suspension)

After this early morning run (45 mins), we pulled over and shut down for about 15 mins. Got back on the bike and headed out on another run. Bike was a dog. Like a completely different bike. No power, running hot, couldn't get out of its own way. No engine lights. 50% or more loss of power. I nurse it to a gas station and call the local HD dealer for advice. The local HD dealer had a dealer rep in house and said it sounded like a sumping issue.

He said to turn the fans on (wethead bike) and let the bike idle on the kickstand for a while. I had no idea what "awhile" was but I think I let it idle for about 10mins. He said the idling would allow the high-vol low pressure side of the oil pump to clear out the crank before I started riding again. Sure enough the bike was much "healthier" after I let it idle for a while before riding.

I dropped the bike off at my local dealer today for inspection and diagnosis. Dealer had already gotten a Reference # for service from HD. I just got word from the dealership that HD authorized the motor to be opened up to inspect the piston jets. They are also overnighting a new design oil pump that will be at the dealer tomorrow morning. Dealer says he'll know more after the engine is fully broken down and the new oil pump arrives. Currently the engine is partially opened up and no issues identified so far.

This might be a good thread for others with higher hp sumping issues on the new M8s to share their experiences.

 

Just to clarify, don't know whether that bike is oil cooled or liquid?

 

2017 CVO - twin cooled

 

Alright, I'll post my experience so far.

I bought a 2017 Ultra Limited (air, oil and water cooled). I put 500 miles on the bike, and then brought it in for the stage III upgrade. I did a stage III and swapped the cam on the stage III kit for a torque cam, not the power cam.

I also had a few other extras added that I won't go into detail for obvious reasons.

I rode the bike for a while with no issues. Granted, I was keeping the bike to 3000-3500 RPMS during this time. I then went and got the bike tuned. I got the bike tuned at 1500 miles with the current setup. I got the spec sheets and saw the SAE chart which showed 109 HP and 126 TQ. The STD Chart gave me 112 HP and 130 TQ. Then the final run, it doesn't say if its SAE or STD, says "uncorrected" and gives me 115 HP and 133 TQ. I am not an expert, so I couldn't even begin to tell you what all that means, other than maybe he played with the numbers? I don't know.

All I know, is the bike felt night and day difference. Had a LOT better throttle response and it was a BEAST compared to how it was before. It wasn't a slouch before either.

So I did a little 5 mile test run on the bike, came back, paid and left happy. I had about an hour commute back to my house from the tuner. I was cruising at highway speeds with cruise control on for about 45 minutes. I came across slower traffic, twisted the throttle to change lanes, and nothing. No power. I couldn't get the bike to go from 75 to 80 mph to save my life. I limped the bike home. The smell was god awful, burning oil basically. Sumping had begun.

The next day the bike rode fine. I rode the bike on an off for a week with no issues. Then on a weekend I go for a long ride, and the same exact problem happens, so I take the bike and drop it off. Dealer takes care of me, and I go ahead and upgrade from a stage III to a stage IV. I was told the clutch on the M8 is only really rated for 130 TQ and it was going to or was slightly slipping now with the bike pulling 133 lbs of TQ. The stage IV comes with a stronger clutch I believe, so it made sense.

I get the stage IV installed, leave and the bike is running stronger than before. It "felt" significantly stronger than my stage III setup. I planned to put 500 miles on it staying between 3000-3500 RPMS and then getting it tuned.

I made it to 617 miles with no problems. Same scenario as before, I am on the highway with cruise control on. Noticing no problems. I go to pass a car, twist throttle and nothing, no power. I get home, god awful smell from the burning oil I assume and by the way, your fuel mileage goes to nil! I burned 3/4 a tank on a trip that should have barely gone through 1/4 tank if that.

Bike is back at the dealer waiting to see whats what.

A few of you have mentioned an improved oil pump? Do you have a part number for it? I'm sure my dealer will look into that. They already replaced the oil pump on mine when I went from stage III to stage IV. However, the problem persisted. I am curious if the new pump is different than what they put in my bike.

 

Heatwave, what is this sumping issue you mention? Not sure what your referring to!!!!!

 

My understanding is there are 2 issues that may need to be checked out.

1) The oil jet sprayers need to be checked to ensure the screws that hold them in place are tight. Supposedly HD has a new trq spec for these screws.

2) A newly designed oil pump (no part # yet that I'm aware of) with a sump side orifice that is "SMALLER". Even though this is a low pressure high volume pump designed to remove oil from the crank area...a SMALLER orifice will increase the velocity of the oil being sumped. One of the engineers on this forum will have to help me understand how a smaller orifice on the sump side will improve oil discharge from the crankcase.

Thats all I have for now but so far the MoCo has been standing behind everything. This comes with the territory of being on the cutting edge of new technology. So long as HD's solution is a long term solution that they stand behind, I support them fully as they make a quick design improvement that should benefit all. I still view the bike as a terrific engineered machine!

 

Keep us posted for I have the Stage lll and want to ensure I too have the latest pump. I will share that I had one of the early pump issues that had to be replaced due to debri in it causing no olio pressure, that was right after my Stage lll upgrade so at this time not sure which oil pump I have.

 

Heatwave, we spoke earlier in the oil pump thread. I'm just letting all know I have had the same issue. So far HD and the dealer that fixed mine were as good and responsive as I could expect.

 

I described it above. Essentially the oil is building up in the crankcase from the low pressure sumping oil pump falling behind the input of oil to the top end. Essentiially the crank gets immersed in too much oil and the bike will feel like its dragging an anchor. Its a dramatic change in power loss from when the bike first starts out as the oil builds up.

At first you can whip the throttle and the bike will explode forward. Once the sumping builds to a certain point, the crank gets immersed and when you turn the throttle slow or fast....nothing happens. The bike will barely accelerate. If you have it...you'll know! Supposedly its a factor of how fast the bike can rev. The oil volume builds up due to the more powerful, faster revving stage 3/4 engines.

 

Same here. Dealer and MoCo have been quick to respond to the issue from my perspective.