103 vs 107 Harley engine

[HardDrive]

There are a bazillion HD specific places to post a question like this, but I figured I would shake the trees here. Anyone have experience with the HD 107 motor? I sold my 88ci Road King, first Harley and I liked it. Was focused on getting an 103, but I sat on a used 107 in the dealership, started it up....quite a bit smoother than the 103, at least at idle.

Pretty big price gap on a 103 vs 107 wondering if the 107 is worth it.

[flatbutt]

Is it the Milwaukee 8 107?

[Jeff Higgins]

The 103 would be a Twin Cam, and by most accounts the best of that breed. The 107 would be the Milwaukee 8, an entirely different engine that replaced the Twin Cam.

The Twin Cam is, to me, an inherently better design. It fixes the problem with horribly splayed pushrods shared by all single camshaft Harleys up through the Evo and inexplicably reintroduced on the Milwaukee 8. The Milwaukee 8 also introduces four valve heads, a needless and silly complication on a motor that will never see even 5,000 rpm. Another needless complication is the water cooled heads introduced on later TC Electraglides (but not on other TC models) and carried through to (I believe) all M8 models.

The difference in idle you feel is because HD made a conscious choice to lower the idle speed on the M8. It idles several hundred RPM lower than the TC, which many complained "didn't idle like a Harley". I'm sorry, but all I can hear at that super low idle is the sound of rod bearings and wrist pins self-destructing.

Anyway, real world experience with my TC 103 Road King since I bought it in 2013 tells me it is a fantastic motorcycle. A worthwhile upgrade over the TC88 it replaced. Not just a bigger motor, but one with all of the early bugs worked out. Plus the new frame, and a six speed transmission. And Brembo brakes. Would an M8 be a big enough upgrade to entice me? I've test ridden several. Still have the TC.

[afterburn 549]

The Twinks have some congenital problems that may or may not raise their heads.
Out-of-phase flywheels..Esp if you hot rod it...I know we don't do that...LOL
The cams and cam plate wear out around the 50 to 60 K mark.
the M8 had sumping issues, and I have not followed that to see what the latest fix is.
Pick your poison as all harleys need something.

[Rot 911]

Just like Porsches, every model seems to have a fatal flaw, if not addressed. I owned a 2014 Lowrider with the 103 engine. Never had any problems with it. But it does idle at about 1000 RPMs so you don’t have that old Harley potato-potato sound.

[afterburn 549]

The old shovels which idled much slower had the potato sound.
You can get the Evo to do it , if carbed, , but its pretty hard on the oil Pressure system or lack of.

The newer bikes with fuel injection systems won't do it .

[flatbutt]

Originally Posted by Jeff Higgins

The 103 would be a Twin Cam, and by most accounts the best of that breed. The 107 would be the Milwaukee 8, an entirely different engine that replaced the Twin Cam.

The Twin Cam is, to me, an inherently better design. It fixes the problem with horribly splayed pushrods shared by all single camshaft Harleys up through the Evo and inexplicably reintroduced on the Milwaukee 8. The Milwaukee 8 also introduces four valve heads, a needless and silly complication on a motor that will never see even 5,000 rpm. Another needless complication is the water cooled heads introduced on later TC Electraglides (but not on other TC models) and carried through to (I believe) all M8 models.

The difference in idle you feel is because HD made a conscious choice to lower the idle speed on the M8. It idles several hundred RPM lower than the TC, which many complained "didn't idle like a Harley". I'm sorry, but all I can hear at that super low idle is the sound of rod bearings and wrist pins self-destructing.

Anyway, real world experience with my TC 103 Road King since I bought it in 2013 tells me it is a fantastic motorcycle. A worthwhile upgrade over the TC88 it replaced. Not just a bigger motor, but one with all of the early bugs worked out. Plus the new frame, and a six speed transmission. And Brembo brakes. Would an M8 be a big enough upgrade to entice me? I've test ridden several. Still have the TC.

My 114 really has what I feel is a very rough idle. Other than that I haven't any sump issue or performance complaints. Then again I only have 8000 miles on it.

Yet when I was considering the purchase most MOCO riders told me that the M8 was a good motor.

[afterburn 549]

Kiven Baxter says the EVO was the best engine Harley ever made.
Next-
It can be made to produce all kinds of power too.
It just takes $$$$$$$

[Chocaholic]

I believe both engines are very reliable, well into old age. Under the guise that bigger is better, the 107 may hold its value a bit better if you are one to keep a bike for a few years then sell. Not sure if that future value would offset the upfront cost.

Bottom line, ride both and buy the bike that you find the most enjoyable. I don’t think you can make a wrong decision.

[Jeff Higgins]

Originally Posted by afterburn 549

The Twinks have some congenital problems that may or may not raise their heads.
Out-of-phase flywheels..Esp if you hot rod it...I know we don't do that...LOL

Correction - only if you hot rod them. Left with their stock internals, this will never be a problem.

Originally Posted by afterburn 549

The cams and cam plate wear out around the 50 to 60 K mark.

Simply not true. Again, real world experience - my TC88 went 120,000 miles with no issues whatsoever after I proactively swapped out that first gen rear cam bearing. My brother's TC96 Electraglide now has over 100,000 miles with no issues whatsoever, as do my riding buddy John's TC95 Road King (big bore kit on a TC88) and my other buddy Peter's TC96 Heritage Soft Tail. All have accumulated over 100k miles with ZERO issues.

While I was still active in my local HOG chapter there were several serious touring riders with well over 100k (a couple were coming up on 200k) miles on their TC bikes of various displacements who, like the four of us mentioned above, never did anything more than change the fluids, tires, and brake pads.

You really need to stop spreading this misinformation about TC motors. I know you are a diehard Evo guy (and they are great motors in their own right), but continually posting your false narrative concerning TC motors (with which you have no experience) could lead the unwary astray. I've owned and ridden both the Evo (Electraglide) and TC's (two Road Kings), along with an 80" Shovel and three Ironheads. Believe me, the TC is superior in every way. Reliability, longevity, ease (more like lack) of maintenance, power - all of it.

The "problems" you keep bringing up might only happen to those motors whose owners open them up to stroke them, bore them, install wild cams, etc. And there are well documented procedures and parts to use that will eliminate those self induced problems as well. Those of us who leave the motors alone (the majority of those who ride them), and operate them within their tried and true performance parameters, have universally enjoyed unprecedented (for Harley) reliability and longevity, all the while requiring no more than the most basic of maintenance (fluids, tires, brake pads). This is real world - not some nonsense you keep reading on the internet.

Originally Posted by afterburn 549

the M8 had sumping issues, and I have not followed that to see what the latest fix is.
Pick your poison as all harleys need something.

Never heard of this, but I don't know anyone with an M8.

Wouldn't surprise me, though, if this were no more than typical internet Harley bashing. Seems to be the favorite pastime of many Harley riders, especially regarding models they have never owned and have no personal experience with.

Myself, I would not hesitate to buy an M8, if I rode one and it knocked my socks off compared to my current bike. I've ridden them, and they have not (yet), so I'll stick with my TC. There is nothing about the mechanical reliability that would keep me off of an M8, however, regardless of what the masses of internet "experts" might have to say about them.

Originally Posted by Chocaholic

I believe both engines are very reliable, well into old age. Under the guise that bigger is better, the 107 may hold its value a bit better if you are one to keep a bike for a few years then sell. Not sure if that future value would offset the upfront cost.

Bottom line, ride both and buy the bike that you find the most enjoyable. I don’t think you can make a wrong decision.

Best advice on this thread. You just can't buy a "bad" Harley these days. Or, really, any bike for that matter. We really are in "the best of times" when it comes to cars and bikes, everything has gotten very refined and reliable. Pick the one that puts the biggest grin on your face and never look back.

[afterburn 549]

Jeff, I suggest you wander in and out of some mom-and-pop harley shops or look on line about cam and cam plate problems.
I have personally seen plenty
Sumping with the M8?
You are just not hooked up!
it has been a HUGE problem!
I have personally seen plenty.
Simply put, for sure I have no reason to make this stuff up.
Go research it.

[Jeff Higgins]

My "research" has been done on the road (as opposed to the internet). Myself and a circle of relatives, friends, and acquaintances who have collectively logged hundreds and hundreds of thousands of miles, dare I say in excess of a million shared miles on TC generation bikes. Many of these bikes (including one of my own) have exceeded 100,000 miles, a few 200,000 miles. Not a single one of them has had any of the issues you keep bringing up. Not a one.

And you are right, I am clueless on M8 bikes. No one I know rides one. I said that already. As such, I'll refrain from commenting on their "issues". I won't simply regurgitate what the self proclaimed "experts" on the internet have to say about them. I'll only discuss that with which I have had personal experience, be it motorcycles, guns, or whatever.

[Jeff Higgins]

Believe me, I absolutely respect your efforts on your Evo. Fantastic stuff. But, well, once again (this is far from the first time), you have veered wildly off course from what the OP was asking.

Stock TC 103 vs. stock M8 107. Can't go wrong with either. The TC 103 is markedly cheaper. Is the M8 107 worth the price difference? I responded with real experience on the TC. You responded with irrelevant nonsense regarding the problems with hot rodded TC motors, and have now gone on to share your (admittedly very cool) adventures in hot rodding your Evo. You have done this quite often. Wash, rinse, repeat.

[911boost]

My stock M8 117 has been rock solid for 16,000 miles so far.

It replaced a TC88, so was a noticeable difference here in altitude riding 2 up.

[afterburn 549]

Jeff when i was a very young man I was hired by a Harley shop.
Why?
Cause I had bought a wrecked Harley from them and made it work again. (very wrecked)
The owner decided I might be an asset?
His name was Fred and he owned several shops in Puget sound.
I just looked him up and he has passed.
Maybe my point, ? I think,?
I have been in the thick of Harley crap for the long time.
Albeit I did not last long at the harley place as it bored the crap out of me and other stuff.

https://www.evanschapel.com/obituary/fred-smith?fh_id=13141

Next- to get you on the correct pathway here-i google this is in 10 seconds about Twink problems


What Are Some Common Twin Cam 96 Problems?
Prouse through this link
Commonly found in Twin Cam 96 engines, are three main problems:
https://theseasonedwrench.com/is-the-twin-cam-96-a-good-motor/
Cam Chain Tensioner Failure
Bearing Failure
Oil Sumping

[afterburn 549]

Here is a little more info
Most everyone know these things, as it is very old news
https://www.msn.com/en-us/autos/motorcycles/common-problems-with-the-harley-davidson-twin-cam-engine-and-which-years-to-avoid/ar-BB1p7CQP


Then there's the crankshaft. Again, it's not quite as common as the twin cam's two biggest issues, but there have been instances of crankshaft runout. It's basically when the camshaft -- possibly from manufacturing, maybe due to wear and tear -- goes off-center. Even a few thousandths of a millimeter of distortion can cause excessive vibrations or wear down the engine a lot faster than normal, as well as making lots of noise, though seemingly this particular problem happened more often in modified (stage two and three) twin cams.
------------------------------------------------
Twin Cam engines also used plastic chain tensioners, which is essential when it comes to keeping enough tension in the timing chain (for synchronizing crankshaft and camshaft rotations). As you might expect, plastic doesn't hold up as well over time as metal. This often resulted in the chain tensioners wearing down rapidly, with plastic shavings from said wear usually making their way into other vital areas. Like the oil pump, which would then lead to engine failure because lots of essential parts weren't being lubricated properly.

[Jeff Higgins]

Why are you deleting posts from an active, ongoing conversation again? It makes me look like I'm having a conversation with myself, with some of my answers to your now deleted posts appearing to make no sense.

We've been through this before - you go ahead and fire up your Google and search to your little heart's content. Myself and my TC owning buddies will fire up our motorcycles and go for a ride.

We have all been around long enough to know how this game is played. Search for whatever it is that you would like to "prove", ignore any results that run contrary to your position, and then only share with the rest of us that which "proves" you are "right". We see this game played on this forum (particularly on PARF) every day. It's rather disingenuous.

So, like I said, go ahead and give your Google a good little workout "proving" just how "terrible" the TC is. While you're doing that, my buddies and and will just keep rolling up trouble free, worry free miles on ours.

[afterburn 549]

The Post was deleted as by your observation and wisdom it was out of context.
I just post facts Jeff.
Ask ANY knowledgeable shop and you will quickly learn some things!..
Carry on and think what you want.
The Twinks are famous for cam and out-of-phase flywheels.
Where do you think "welded flywheels" came from?
Several companies make their living from this congenital problem. (Call Dark horse ) https://darkhorsemoco.com/
Argue with yourself.

I am done.
Luv them if you want, IDC

https://riderhow.com/engine-problems-harley-davidson-88-107-110-114/

[Jeff Higgins]

Originally Posted by afterburn 549

The Post was deleted as by your observation and wisdom it was out of context.
I just post facts Jeff.
Ask ANY knowledgeable shop and you will quickly learn some things!..
Carry on and think what you want.
The Twinks are famous for cam and out-of-phase flywheels.
Where do you think "welded flywheels" came from?
Several companies make their living from this congenital problem. (Call Dark horse ) https://darkhorsemoco.com/
Argue with yourself.

I am done.
Luv them if you want, IDC

https://riderhow.com/engine-problems-harley-davidson-88-107-110-114/

No wonder you are confused. The link you provide right here pretty much says it all regarding those who you trust for their technical expertise. There are some real gems contained in that link, here are some of the highlights. Direct copy and paste from your provided link:

Inadequate Cam Chain Tensioners

The plastic cam chain tensioners can’t take as much stress from the pinion shafts.

They require regular inspections and need to be frequently changed every few miles.

If they disintegrate from weariness, the metal-to-metal contact in the shaft will generate heat issues and subsequent engine failure.


"Disintegrate from weariness???"


Unreliable Crankshaft

The pressed-up crankshafts were one of the biggest issues with the Twin cams.

Harley assembled the engine models in this manner to reduce the production costs back in ’98.

Users discovered that the pressed-up crank resulted in complete engine breakdown in less than 2000-3000 miles.

Especially if you were riding fast and hot.

Essentially, the spline shaft from the back would force down on the left flywheel, causing misalignment.

The misaligned flywheel would then shift or even bend the crankpin, causing engine failure.

Most Possible Solutions?

If the crankpin shifts or breaks off, it can tear off the entire cam system.

The broken parts will circulate through the system, and do more damage to the healthy body parts.

Hence, the primary solution is to locate the broken pin and remove it completely.

Multiple mechanical experts suggest replacing the unreliable crankshaft altogether.

You can escape both crankshaft and tensioner issues with an upgraded and balanced Harley 88.


Wow - total engine failure in 2,000-3,000 miles? Yup, best to "locate and remove it completely" before it can "do more damage to the healthy body parts". And you believe this nonsense.


Loose Pistons

The powerful M8 engine can render the pistons very loose when revs get too intense.

The metal-to-metal friction between the loose pistons can contribute to heating issues.


I bet metal to metal friction between loose pistons would actually create some issues.


Most Possible Solutions?

The major heating issues have since been resolved by Harley in the newer models.

Anything from 2009 and up shouldn’t have any significant heating problems.

Different specialists suggest removing the stock head pipe and placing a catless pipe instead for better circulation of air.


Not sure what to even say about that one. But, well this one takes the cake:


Slow Starting

The engine, despite being in pristine condition, can take a long time to start, especially in low temperatures.

Under 50-60° F, the charged battery takes longer to heat up the engine, which contributes to the slow response.


Do you even read the nonsense you link? Apparently not. Not only did you fail to notice (or at least acknowledge) that in your very own links they say that the crankshaft clocking issue is restricted to hot-rodded motors (I pointed this out right away above), you apparently missed this, from one of the first links you posted, in its Frequently asked questions, down towards the end:

https://theseasonedwrench.com/is-the-twin-cam-96-a-good-motor/

Is the Twin Cam 96 a reliable motor?

Yes, the Twin Cam 96 has a reputation for reliability and longevity, especially when properly maintained. Regular servicing and using quality parts and fluids can contribute to the engine’s durability and performance.


Nowhere do any of your assertions contain any measure of frequency of occurrence. Every other one? One in ten? One in one hundred? One in a million? Nothing. Nada. Zilch.

In conclusion, every mechanical object is going to have some failure rate. Everything. The fact that there are millions of TC bikes out there, manufactured from 1999 through 2017 that have never experienced the dire failure modes you breathlessly try to warn against is completely lost on you. And their continued reliability just makes you sound like a shrill old fool.

[afterburn 549]

Call any shop Jeff, Just t any.
I dare you to try it!
Tell me who you called and their name, please.
You see, I have no romantic involvement in machinery.
It's all nuts, bolts, and parts to me .
Helicopters to Harleys, it parts.
Starting with the Evo they dropped a lot of tapered parts.
The Pinion at first. (which I had problems with until I welded it.
Next, Starting with the Twink they now have more problems and crank runouts.
This problem spirals through the M8.
The old shovel was allowed about 1.5 thou. for run out.
The Twink are allowed somewhere near 4!
What happened? (they had no choice but to allow more, because of the pressed-together cheep cranks)
The wobble in the wheels ruins the cams.
I knows what I knows Jeff.
Call your favorite experts and ask them.
Call Dark Horse .
Call S&S.
Call someone!
Everyone knows except for you!

Here is a number Jeff, to start with , call these guys.
Plus I can list you quite a few more if you like.
Ask for Paul.
http://www.gosloinc.com/