I just added one of those oil dipsticks with LED temp readout.

What temp should I be happy to see?

What temp should I worry about?

 

Hi,

Got my first Harely this year after riding metrics for nearly 25 years, my first reaction was damn does this thing runs hot!!!!

So I bought one of those 100.00 things too. First thing I learned was that they are known to be inaccurate. I boiled mine in water along with a digital and analog meat thermometer. The second problem you may encounter is that they have a problem with moisture getting into them, once that happens the heat makes the water vapor fogs the thing so that you can't read it. I've had this happen to two of them so far. My first one was dead on for temp accuracy, the second was off by 5 degrees.

Okay, that being said, my '05 Ultra ran at 285, I've seen it as high as 292 with the regular oil, 270ish with synthetic (I put in synthetic at my 1K service). Folks on this list have said that dino oil is good up to 250 (that's scary if you look at my temps prior to synthetic at my 1K) and synthetic is good up to 300. At least that's what I beleive the numbers were, someone will jump in if I'm wrong on this point. I felt the bike ran hot, but at the 1k and 5K service was assured all was fine. On a hot day 90+ degrees out and on a fund raising run (slow moving traffice with a lot of bikes, my passenger said NEVER AGAIN!) Her leggs were almost getting burned. I can't imagine riding it in the summer with shorts, I doubt my thighs could take it.

I plan on putting on an oil cooler this fall/winter once things quiet down at the local HD service shops. I hope this gets the temp down another 10 degrees or so. And once the warranty is up (2 years away, I'll run mobil's synthetic, I hear that will lower a bit more).

Joe

 

Normal operating temps range from 200 - 250* depending on the build and size of the motor.

Just a bit of info

https://www.hdforums.com/m_64815/tm.htm

 

Very dependent on outside air temp, and how hard you are riding. I have seen a high of about 250, but normally around 200-225.

'04 Road King with Synthentic oil.

 

I ride an 03 Ultra with an oil cooler. Before I put the clooler on I was riding in 100 degree weather and was burning my legs. That was also before I had an oil temp guage put in place of the ambient guage on my dash.
I don't remember, but I think I was running Harley 20-50 and my bike was still an 88.
So, after those installs I kept a better watch on the temp.
Of course, depending on the weather my bike runs between 170 and 250. When it's at 250 my engine sounds like it's pistons are changing holes. very noisy. All the Harley mechanics I have talked to say that the engines are built to run hot. Hmmmm. Gonna have to wear heavier pants in hot weather.
Anyway, I now have 95 cubes and run Screaming Eagle Synthetic. Seems to run cooler on synthetic. On my next oil change I might try some of that purple synthetic.

Good luck.