Here's a couple report links that you might find helpful with this issue.

Milwaukee-Eight - Dyno Charts & other Interesting Info

Why & How to Cool Down the Twin Cam & Milwaukee-Eight Engines

 

A few years back I heard from one of the service reps at BHHD that the MOCO suggested operating temp was 180-220 which to me seems about right.
Anything more you can feel it.
I bought a set of used Wards Fans from a member here and my next move will be an Ultracool oil cooler.
Those two things should keep it cool-er.
Bike seems to run better when it is cool too.

 

Put exhaust and tuner on it. Then take to a dyno for a true tune. Don' rely on the canned tunes. You will see a huge difference in heat and performance.

 

I am currently running my 2010 Dyna Super Glide with the 96 ci twin cam. It is stage one tuned with the Vance and Hines Propipe 2 into 1 and the Screaming Eagle high-performance air cleaner. It always ran what I felt very hot to me but got great mileage {50 consistently}.

I finally added the V&H FP3 Fuelpak tuner as it was obviously running waaaay too lean moving all that additional airflow with the stock tune. I reflashed the ECM to reflect the change from stock and WOW! The difference was immediate and dramatic. As predicted by the tec's at V&H I lost 4 mpg but the motor cooled down at least 30 - 40 degrees. It seems to pull harder with the performance at any rpm vastly improved.

I am considering going to a 2018 Heritage Classic with the 114 motor but am wondering if excess heat is going to be an issue. Anyone running a 114 HC?

 

One consideration is the Ultra is, I think, the only bike that still has lowers but is not liquid cooled. You might try taking off the lowers and see how much of a difference that makes. I realize that's not a great answer if you like the lowers, but the heat difference can be considerable and for me the trade off is worth it. I'm not trying to start the back and forth about whether the lowers make the engine actually run hotter, but I think it's pretty clear that the rider feels more heat with the lowers on.

 

 

I bought a new 2107 HD Ultra in December 2016. It has the “precision oil cooled” engine, not the water cooled engine. I prefer to keep it simple and I figured that was one less system to cause problems or leaks.

Since I bought it in the winter, I rode it on reasonably nice days (temps in the 40’s) in January and February. I noticed that the Engine Idle Temp Management System (EITMS) would activate and go into one-cylinder operation at idle at stops. I thought that odd, but figured Harley set the trigger temperature fairly low to make sure the engine didn’t get too hot at stops.

As the weather warmed up, I noted that the EITMS would activate all the time at stops. I also noted that it seemed very hot right under the tank, with the “hot smell.” I figured it was because the bike was new and all the coatings hadn’t been baked yet.

I have a Dynojet PowerVision that I had on my previous bike, a 2008 Electraglide Classic (96” engine, 37,000 miles when I traded it in). I wanted to put it on the new bike to monitor temps and other data from the ECU. I liked being able to do that on my old bike. I had to order a new cable from Dynojet because the new bikes use a 6-pin data port, whereas my old bike used a 4-pin data port.

When I plugged it into the data port, and went for a ride, I saw the temps rapidly rise to and then well above 300 degrees during regular riding on cool to moderate days, not hot days in stop and go. The temp readout got up to the 350-360 range on 70-80 degree days in highway riding (again, not stop and go traffic). Now I was beginning to get concerned and wondering if the temperature sensor was faulty, so when I got home from one ride I got out my Milwaukee Tools infrared thermometer and aimed it at the rear cylinder head near the spark plug, and it read 357 degrees. That’s literally hot enough to cook on! In contrast, my 2008 EG would get to about 240-250 degrees in highway riding in similar conditions. That’s over a 100-degree difference! NOTE: I have NOT changed the tuning; I'm only using it to read data from the ECU.

I then took the bike back to the dealer in Fairfax Virginia to ask about the high temps. The service manager said that they couldn’t rely on an aftermarket temperature measurement, and asked if I had the Check Engine Light come on. No it hadn’t, so he said that if the engine was overheating, the CEL would come on so he didn’t think anything was wrong. He agreed to read the ECU codes and check for anything odd at my next service (5000 miles, probably in a month or two).

If there isn’t any CEL, I doubt they will see any stored codes indicating overheating. So, now I’m thinking about what else might be wrong, or whether the new M8 engine has some serious design flaws (wouldn’t be the first time for the MoCo). This kind of heat will eventually cause cracks in the head (most likely between the exhaust ports), prematurely worn valve guides, possible coking of oil, piston ring failure, and other possible problems.

Has anyone else measured the temps on the new M8 oil-cooled engine yet? Am I the first to find this out? Or maybe this is only a problem with my engine (oil jet or return line plugged or something like that).

Until this is resolved, I suggest that any of you considering buying a new M8 oil-cooled bike to either wait, or go with the water-cooled engine, and get a 4+ year extended warranty to go with it. Fortunately, I did.

 

 

"Has anyone else measured the temps on the new M8 oil-cooled engine yet? Am I the first to find this out? Or maybe this is only a problem with my engine (oil jet or return line plugged or something like that).

Until this is resolved, I suggest that any of you considering buying a new M8 oil-cooled bike to either wait, or go with the water-cooled engine, and get a 4+ year extended warranty to go with it. Fortunately, I did."
we have instance of one bike probably running hot then suggest there may be a problem with the other 120,000 made over last two years this kind of logic blows my mind. Until this is resolved i suggest they shut down the assembly line in Milwaukee Pennsylvania Thailand India etc this is some serious s#$t next time a warning light could come on.

 

Any particular reason you're posting up this issue again? Didn't' like the answers on the thread posted on the seventh?

But I will give the answer that I wanted to give on the previous thread. If this disturbs you, I don't believe this is the bike for you. There is info all over this forum...and others...and I believe in your previous thread. ..on strategies to mitigate this. But the bottom line is that it's an air cooled engine that's expected to operate in an era of politically correct restrictions.

Along with the 'badassery' of riding a Harley comes a price. I reckon.

Good luck in your quest.