Milwaukee Eight (M8) 2017 and up M8 Air and Liquid Cooled discussion
Sponsored by:
Sponsored by:

Engine Temp

Thread Tools
 
Search this Thread
 
Old Jun 19, 2020 | 07:19 AM
  #1  
leftyjm's Avatar
leftyjm
Thread Starter
|
Road Warrior
Veteran: Air Force
10 Year Member
Liked
Community Favorite
Joined: Nov 2014
Posts: 1,438
Likes: 448
From: Midwest
Default Engine Temp

I have the 107 on my Heritage with a Stage 1
I only have about 500 miles on it but this thing feels like it runs real f’ing hot compared to my 103 with the same set up, although the tuner on the 103 is a Power Vision and a Screamim eagle on the Heritage.
The 107 is still running very lean.
Anybody else feeling the heat?
 
Reply
Old Jun 19, 2020 | 07:39 AM
  #2  
Harttoo's Avatar
Harttoo
Road Master
Veteran: Army
10 Year Member
Liked
Joined: Feb 2014
Posts: 1,240
Likes: 170
From: Wisconsin
Default

More displacement,more heat.
 
Reply
Old Jun 19, 2020 | 07:53 AM
  #3  
OldMike's Avatar
OldMike
Seasoned HDF Member
15 Year Member
Liked
Loved
Community Favorite
Joined: Feb 2009
Posts: 5,641
Likes: 1,985
From: Cleveland Zoo
Default

Originally Posted by leftyjm
I have the 107 on my Heritage with a Stage 1
I only have about 500 miles on it but this thing feels like it runs real f’ing hot compared to my 103 with the same set up, although the tuner on the 103 is a Power Vision and a Screamim eagle on the Heritage.
The 107 is still running very lean.
Anybody else feeling the heat?
Maybe it's the tuner, on my 114 I'm not noticing more heat compared to my past 2014 103. I didn't measure, I don't have a number, just what I feel.
I also think the routing of my rear exhaust header pipe helps with the felt heat on my current bike.
 
Reply
Old Jun 19, 2020 | 08:01 AM
  #4  
Gorion's Avatar
Gorion
Road Captain
Veteran: Navy
Veteran: Coast Guard
15 Year Member
Community Favorite
Joined: May 2007
Posts: 547
Likes: 389
From: PNW
Default

The 103 on my night train was definitely hotter (seems to me anyway) than my 107 LR
 
Reply
Old Jun 19, 2020 | 08:55 AM
  #5  
SoCaRider's Avatar
SoCaRider
Road Captain
Joined: Feb 2020
Posts: 615
Likes: 208
From: California
Default

My 114 is running about 260 right now 80 sothing degree weather
 
Reply
Old Jun 19, 2020 | 08:58 AM
  #6  
mjwebb's Avatar
mjwebb
Seasoned HDF Member
15 Year Member
Photogenic
Community Builder
Top Answer: 1
Joined: Jan 2008
Posts: 13,593
Likes: 11,288
From: State of Confusion
Default

Originally Posted by leftyjm
I have the 107 on my Heritage with a Stage 1
I only have about 500 miles on it but this thing feels like it runs real f’ing hot compared to my 103 with the same set up, although the tuner on the 103 is a Power Vision and a Screamim eagle on the Heritage.
The 107 is still running very lean.
Anybody else feeling the heat?
no different really than all the Harleys we've had in the last 15 years..well maybe some but I don't pay attention to it, as loooooong ago I accepted the fact that I'm choosing to sit on top of a combustion engine that's attached to two wheels
 

Last edited by mjwebb; Jun 19, 2020 at 08:59 AM.
Reply
Old Jun 19, 2020 | 09:05 AM
  #7  
Wmitz's Avatar
Wmitz
Road Master
10 Year Member
Photogenic
Liked
Joined: Feb 2014
Posts: 804
Likes: 237
From: TN
Default

Get a multi bike license for the vision. The se tuner will not allow to much change, as it is a licensed epa tuner. Also look into DK Customs tank lift and cooling deflector wings. I am currently using the 1.5 inch lift with the wings, it does work.
 
Reply
Old Jun 19, 2020 | 11:08 AM
  #8  
KrustyKush's Avatar
KrustyKush
Road Master
Joined: Jan 2016
Posts: 1,143
Likes: 433
From: Menifee, CA
Default

Now entering my third SoCal summer on the 2018 RGU. At 34k miles, I'd say the stock 107 is noticeably cooler running than the stock 2016 103 FLHTCU it replaced. The 2016 103 on a 95 degree day in steady city traffic would just about blister my right thigh. I don't get this on the 2018 M8.

I recently re-read the Cycle World introductory article from 2016 on the then-new M8. In the article, Kevin Cameron states that HD claims the M8 runs cooler than the 103. I'd have to agree with this. It "feels" cooler to me.

But, that isn't an impression gathered after a short ride on a hot day, but rather an impression created after several summers of riding in all kinds of weather and traffic. And there is the point that I would make for the OP: 500 miles is probably too short a time of riding to develop very firm opinions about engine heat. Or saddle comfort, or tires, or just about anything else. Give yourself lots of time and plenty of miles. First impressions are almost always wrong.
 
Reply
HD Forum Stories

The Best of Harley-Davidson for Lifelong Riders

story-0

8 Best Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-1

10 Worst Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-2

Killer Custom's Jail Break Is The Breakout That Refused to Blend In

 Verdad Gallardo
story-3

Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

 Verdad Gallardo
story-4

Harley-Davidson Reveals Super Cool Cafe Racer Concept

 Verdad Gallardo
story-5

Engraved Rebellion: Inside Bundnerbike's Glam Rock II

 Verdad Gallardo
story-6

10 Motorcycles You Should Never Buy

 Joe Kucinski
story-7

10 Things Harley-Davidson Needs to Fix in 2026

 Verdad Gallardo
story-8

Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider

 Verdad Gallardo
story-9

The Best and Worst Harley-Davidson Moves of 2025

 Verdad Gallardo
Old Jun 19, 2020 | 11:47 AM
  #9  
mjwebb's Avatar
mjwebb
Seasoned HDF Member
15 Year Member
Photogenic
Community Builder
Top Answer: 1
Joined: Jan 2008
Posts: 13,593
Likes: 11,288
From: State of Confusion
Default

Originally Posted by KrustyKush
Now entering my third SoCal summer on the 2018 RGU. At 34k miles, I'd say the stock 107 is noticeably cooler running than the stock 2016 103 FLHTCU it replaced. The 2016 103 on a 95 degree day in steady city traffic would just about blister my right thigh. I don't get this on the 2018 M8.

I recently re-read the Cycle World introductory article from 2016 on the then-new M8. In the article, Kevin Cameron states that HD claims the M8 runs cooler than the 103. I'd have to agree with this. It "feels" cooler to me.

But, that isn't an impression gathered after a short ride on a hot day, but rather an impression created after several summers of riding in all kinds of weather and traffic. And there is the point that I would make for the OP: 500 miles is probably too short a time of riding to develop very firm opinions about engine heat. Or saddle comfort, or tires, or just about anything else. Give yourself lots of time and plenty of miles. First impressions are almost always wrong.
yeah, I think in Kevin's interview with the Chief M8 engineer it was stated the exhaust valve ET area was 100 degrees cooler than the TC
 
Reply
Old Jun 19, 2020 | 11:53 AM
  #10  
TriGeezer's Avatar
TriGeezer
Seasoned HDF Member
Photogenic
Photoriffic
Shutterbug
Joined: May 2012
Posts: 32,934
Likes: 36,027
From: Carlsbad, CA
Default

Go out and sit on your car motor after it comes up to temperature, for comparison.

My 103 with SE255 cams, Jagg oil cooler with fan, and wards head fans, definitely ran hotter than my twin cooled 107 M8. But, my 103 had full catless V&H exhaust, whereas my M8 still has the cat. So, on my M8...my right heel gets hot!
 

Last edited by TriGeezer; Jun 19, 2020 at 11:56 AM.
Reply



All times are GMT -5. The time now is 04:07 PM.

story-0
8 Best Harley-Davidson Motorcycles Ever

Slideshow: Not every Harley gets it right, but these are the ones that genuinely earned their reputation.

By Pouria Savadkouei | 2026-04-15 14:23:21


VIEW MORE
story-1
10 Worst Harley-Davidson Motorcycles Ever

Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.

By Pouria Savadkouei | 2026-04-01 20:01:09


VIEW MORE
story-2
Killer Custom's Jail Break Is The Breakout That Refused to Blend In

Slideshow: Killer Custom's "Jail Breaker" build focuses more on stance and visual aggression than mechanical overhaul.

By Verdad Gallardo | 2026-03-18 19:20:32


VIEW MORE
story-3
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.

By Verdad Gallardo | 2026-03-07 16:15:30


VIEW MORE
story-4
Harley-Davidson Reveals Super Cool Cafe Racer Concept

Slideshow: Harley-Davidson's new RMCR concept revives the café racer formula with modern hardware-and it may be exactly the reset the company needs.

By Verdad Gallardo | 2026-03-04 12:23:37


VIEW MORE
story-5
Engraved Rebellion: Inside Bundnerbike's Glam Rock II

Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.

By Verdad Gallardo | 2026-02-24 18:19:44


VIEW MORE
story-6
10 Motorcycles You Should Never Buy

Slideshow: There is no shortage of great motorcycles to buy, but we would avoid these ten.

By Joe Kucinski | 2026-02-19 14:50:51


VIEW MORE
story-7
10 Things Harley-Davidson Needs to Fix in 2026

Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.

By Verdad Gallardo | 2026-01-13 18:33:17


VIEW MORE
story-8
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider

Slideshow: Graeme Billington's left-hand-drive Shovelhead is as much about problem-solving as it is about classic Harley form.

By Verdad Gallardo | 2025-12-30 11:27:08


VIEW MORE
story-9
The Best and Worst Harley-Davidson Moves of 2025

Slideshow: A clear-eyed look at what actually worked for Harley this year, and what quietly undermined its progress.

By Verdad Gallardo | 2025-12-29 17:10:48


VIEW MORE