Consensus question: Do M8’s burn oil?
Road Warrior
Joined: Aug 2014
Posts: 1,937
Likes: 320
From: Vancouver, WA
I remember back in 90 when I bought that F150 a gearhead told me a story. He said when he was a kid in 68 he got his Father to co-sign a loan for a new Fastback Mustang. His Father told him he would only co-sign that loan if he would agree to change the oil and filter every 2000 miles. He still had that car and it still ran great. I adopted that mindset and it has worked great for me.
A mechanic friend of mine showed me an oil filter that he cut open that came off an engine that someone had been told to go 10,000 miles between changes. The filter element had actually collapsed and looked like rotten burlap. It was also charred black.
When I got my new 2023 Ultra last year (didn't want a 2024 in black and I dang sure didn't want a Skyline model) they said Harley had said service intervals were at 5000 miles after the first 1000. I told them to keep the books straight for my warranty I would change the oil and filter (keeping the receipts) at the 2500 mile intervals and bring it to the dealership to have them do the 5000 mile intervals and document it in the computer. Might be the only "new" bike I ever own. I sort of got pushed into getting it when I found out they were discontinuing the classic Ultras in favor of the stripped down bar hoppers and the only new ones on the floor didn't have any chrome on them. All in all I'm glad I did it. I was able to upgrade the audio the way I wanted to because of the classic Rushmore design and adding a SE torque cam really woke up that 114.
With the extra heat in the furnace I'm going to add an oil cooler to it. From just a little bit of sitting if I get into town in traffic you can tell that motor is too hot. The liquid cooled heads just alleviate the felt heat from the rider. The engine itself is actually running hotter than the models with the oil coolers on them. Harley actually recommends running straight 50 weight oil in the owners manual for constant operation above 70 degrees because they know 20W-50 will get trashed in stop and go traffice and thin out like water.
A mechanic friend of mine showed me an oil filter that he cut open that came off an engine that someone had been told to go 10,000 miles between changes. The filter element had actually collapsed and looked like rotten burlap. It was also charred black.
When I got my new 2023 Ultra last year (didn't want a 2024 in black and I dang sure didn't want a Skyline model) they said Harley had said service intervals were at 5000 miles after the first 1000. I told them to keep the books straight for my warranty I would change the oil and filter (keeping the receipts) at the 2500 mile intervals and bring it to the dealership to have them do the 5000 mile intervals and document it in the computer. Might be the only "new" bike I ever own. I sort of got pushed into getting it when I found out they were discontinuing the classic Ultras in favor of the stripped down bar hoppers and the only new ones on the floor didn't have any chrome on them. All in all I'm glad I did it. I was able to upgrade the audio the way I wanted to because of the classic Rushmore design and adding a SE torque cam really woke up that 114.
With the extra heat in the furnace I'm going to add an oil cooler to it. From just a little bit of sitting if I get into town in traffic you can tell that motor is too hot. The liquid cooled heads just alleviate the felt heat from the rider. The engine itself is actually running hotter than the models with the oil coolers on them. Harley actually recommends running straight 50 weight oil in the owners manual for constant operation above 70 degrees because they know 20W-50 will get trashed in stop and go traffice and thin out like water.
Seasoned HDF Member
Joined: May 2008
Posts: 21,184
Likes: 12,762
From: South Carolina
Tourer
Joined: Apr 2019
Posts: 367
Likes: 264
From: Massachusetts
My ‘18 RKS never really used oil other than it puking table spoons of it into the air cleaner. Then I changed the oil pump during the cam swap to a ‘21 or ‘22 design. Completely stopped then.I still have it bypassed to the ground anyway with my HPI air cleaner.
Grand HDF Member
Joined: Sep 2017
Posts: 3,864
Likes: 1,011
From: Southern Virginia
My 2010 Ultra started leaking from that seal at around 30,000 miles, then started leaking from between the engine cases shortly afterwards. By about 56,000 miles it was leaking from the rotor area too. Just pissed oil all over the place. Pretty sad considering I do NOT ride my bikes hard.
Seasoned HDF Member
Joined: Mar 2021
Posts: 18,504
Likes: 3,732
From: backwoods
When I was at dealer last year and guy was complaining, they told him Harley's says 1 quart per 1k miles is acceptable, which has been the company line for decades. How do they keep a straight face?
Should have said then all you need to do is a filter change.
Should have said then all you need to do is a filter change.
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Tourer
Joined: Jul 2021
Posts: 392
Likes: 258
From: Florida
Yes oil consumption.
My 2023 lowrider St uses a quart every 1500 miles. The dealer is monitoring it now. But like the bulletin says the dealer claims 1 quart every 1500 miles is acceptable. I have 8,500 miles on my bike now. I own a leak down indicator. I plan on leaking it down myself alongside a 95 in twin Cam that I built that does not burn oil. According to DK customs the motor company is claiming a 25% leak down as acceptable.
Insane. I will keep you posted about what the dealer says, my bike is currently being monitored every 500 miles. I will start a thread in the engine section after I do a leak down. Shout out to DK customs your videos are great.
Insane. I will keep you posted about what the dealer says, my bike is currently being monitored every 500 miles. I will start a thread in the engine section after I do a leak down. Shout out to DK customs your videos are great.
Seasoned HDF Member
Joined: Sep 2009
Posts: 17,149
Likes: 6,173
From: SE Michigan
Last edited by Keithhu; May 29, 2025 at 06:38 AM.