WHY DO HARLEY FLYWHEELS TWIST?
ฝัง
- เผยแพร่เมื่อ 5 ต.ค. 2023
- The leading causes of excessive run-out are high rpm downshifts, high rpm clutch drops & throttle 'chopping'.
The OEM Flywheel/Crankshaft is fit for purpose & will do hundreds of thousands of kilometres/miles with regular maintenance.
However, if you want to race, wheelie, or skid your Harley, you may need to upgrade the flywheel set.
There is a lot of weight hanging off the left side of the crank & the right side is driving the valve train. - ยานยนต์และพาหนะ
That was one of the best informative video on runout I have seen
Thanks for watching. Glad you enjoyed it
When I downshift I always rev match which I think reduces the stress on the crank and flywheels
Absolutely
Thank you!! So much great knowledge in a 10 minute video appreciate your wisdom 🙏
Thanks for watching! I'm glad you enjoyed it.
Tommy you have answered alot of my questions with this video. Now I know. Thank you for sharing your knowledge. Peace ✌
Love your work. Thanks for the informative video. Keep them coming. 👌👏👏
I love your channel! You teach how to save money by telling us what parts are needed and what Harley parts are good or how strengthen them!
Thanks for watching! Glad you like the channel 😀
Always great info Tommy, fact based! Thanks for always giving us the proper info on upgrading parts. Good, better, best.
Thanks for watching!
Its said by somone else before, the best vid , now I understand what could be the cause of crank runout. I also I understand that downshifting agressivly is not good. And its not ( always) bad Luck when a runout occure. It has a cause and can be avoid. Maybe some guys who have compensator issues AND have a cranckrunout understand that the reason iis ridinstyle.
Thanks agai mate.
Stuff like this is why I’m still glad I picked up another sportster. I know my bike has limitations in two up comfort, etc. At least I have no worries that the bottom end of my iron 1200 will ever have excessive runout.
With that being said, I would still buy a bike with a M8 as I don’t abuse my bikes by doing clutch dumps, burnouts, hard down shifts, etc.
Great video!
As a guy who went from an EVO Sportster to a twin cam 88 I agree with everything you said. If I had known everything that I know now I would have gotten another Sportster.
Great video and thanks for posting! HD focuses on sound, cosmetics and styling. They even use their stock run of the mill engines on their most expensive $50000 CVO's. The M8 is a wonderful platform to build upon with aftermarket parts from Dark Horse , S&S and other top aftermarket companies. Good luck getting 100000 reliable miles on a stock motor, even if its bone stock.
Excellent explanation 🤘⚡️🤘✨✨✨
Excellent presentation. I feel like I've been inside my crankcase.
Thanks for watching 👍
Excellent description. Thanks for the informative vid.
Thanks for watching
Hey @@MasterTechMiller
What symptoms are experienced if the crank does twist? Besides the runout being out of spec, of course.
I ask because I have a wild vibration going through my bike atm, almost rendering it unridable. It happened when I screamed out of a corner and found false neutral. This made the engine rev high (didn’t hit the rev limit though) and an immediate vibration began. I thought it strange, so in order to dismiss the trany as the issue, I pulled in the clutch a gave it a big rev which increased the vibration!
Yes I do burnouts… occasionally, but not from a standing start. Engine was built by Mark Hood Engineering - it’s hard to resist burnouts 😬
I don’t expect a diagnosis from you, just outline some effects a twisted crank has, please?
@dapezent I'm not sure a twisted crank would cause severe vibrations like you are describing as my mates bike had 42 thou of run out. He was rising the bike around & never experienced any noticeable vibrations out of the ordinary.
In saying that though, I guess it is possible if the crank is extremely twisted, but keep in mind, 42thou is huge amount & we could actually watch the crank wobble when rotated.
The balancer gear may have shifted slightly on you. There is a pressed on gear that drives the balancer ahaft. There is a pin on the crank that limits rotating but maybe it's fully shifted and causing the vibration?
I've never seen this happen, and Harley claim that if it does happen there rider would not even know. It's more of safety feature to ensure the balance gear does not shift so far that it collides with the main journal.
Having never experienced a shifted gear I can't give an accurate opinion on what it may feel like.
I would also like the mention that crank cases & main bearings would more that likely be damaged severely if the crank shifted or twisted enough to cause such a violent vibration as you're describing.
Fantastic explanation
Glad you liked it
Anything above 6-7 thou runout at the crank on the cam side and your already damaging your oil pump,this started after 2003 when Harley stopped using the timken bearings in the crank setup (Cheaper), get it trued, install over size solid cank pin and timken bearing, then your good to light it up, of course then you need to ugrade the primary/Trans ditch the drive belt and go to chain, wow, lot of money!
the best video, I've ever seen about flywheels
Thanks for watching! Glad you liked it
I learned something my man! Thank you!
Thanks for watching
Great Job
Great video 👍
Thanks 👍
Great video
Thanks for watching
It's ridiculous that a company that calls themselves "premium" would send cranks like this out the door and eliminate the left side Timken bearing.
this design is fine STOCK and will not twist under stock horsepower, The issue with runout comes when people modify their bikes to put BIG horsepower through it which will naturally cause problems to other stock components if not strengthened accordingly. This applies to almost every engine in existence.
@@Mike-jv8bv Then why did Harley have to loosen the allowable tolerance to avoid warranty claims? These cranks were built with subpar build quality which was aggravated by the penny-pinching elimination of the left side Timken bearing. Harley KNEW about this and ACTIVELY took measures to avoid responsibility.
I agree, rydingstyle is important people who want a lot more horsepower do that with a reason . If you will , everything kan be broken if you wish . Its like using steroids you get a lot more power but you can tear off a musckle / tendon becouse it cant handle the strenght@@Mike-jv8bv
@@Mike-jv8bv if you ride it like an old woman and never rev it or lug it ,yes the cranks wont twist or suffer from excessive run out, then make a post '' Ive done 80k on my Tin Can with zero problems'' ,I know a fellow with a stock Night Train he bought brand new ,lucky if its done 35 K has excessive runout already
@@jamessouthworth1699 ON the twin cams no doubt. The M8 corrected most of these issues now. Harley won't admit it but they hired the germans to engineer the milwaukee 8, that's why it's smooth.
Excellent information! We have all learned a lot here. One question: Why not make a pin with a key on one side, like the pin on Evolution crankshafts? (if it has that key, the pin will not turn) Maybe it can't be done on a cylindrical pin? Thanks for your channel!!!
Thank you. Very informative
HD'S 12thou is scary
Yes, 12thou is a lot however, with the OEM Cam plate & oil pump it does get by. No way would I put one back together with 10thou though.
What’s up man! Thanks for the video. I bought a dark horse crank, including screamin eagle lefty bearings on my 05 Dyna. Converting it to 100ci. Will my runout be an issue even though I have the “bulletproof” dark horse crank? Or is there still possibilities to have issues even though I don’t have the Timken bottom end conversion? Thank you.
I learned stuff. 👍
Question: In this video, i see that it looks like the sprocket shaft side is barely on the bearings of the stand? I've never seen a stand like this. Is it just for checking true? Most stands here that I've seen or used are much lower and beefy.
I have a Lowrider st 2023 with a S&S 475 cam , 55 mm throttle body , 55 injectors , two into 1 Trash in pipe . About 139 torque and 118 hp. It seams fast now , what do you think about going to the 132 S&S . I’m not racing it but like the fun factor . Also have a 128 2020 Road glide special , 55 throttle body , 55 injectors Krome works two into one 475 cam . Is it worth going up to the 132 , and does it get a little hard to handle . FYI use to be HD dealer and build a lot of motors .
When I did my stage 2 on my low rider 2023 with s&s 475 with gear drive, my crank run out was 0,0039. Hope that stays in that value… I don’t do any wheelies and burnouts, just cruising and sometimes I like to pull hard on my throttle 🙏
It will be absolutely fine
@@MasterTechMiller thanks for the reply 👌
That’s why I have a grc
What flywheel do they use in the 135 . Your videos are very good I’m sure it gets a little involved for some . I use to race flat bottom boats and built a lot of engines . Very good info .
4-5/8" Stroke on the 135ci engines. The 114ci engines run a 4.5" stroke & the 107ci engines run a 4-3/8" stroke.
@@MasterTechMillerI have a 2019 sg with the 107 but I’m going to upgrade to a 129” big bore kit with 550 gear cam. What flywheel do you recommend or will be better to get the stock flywheel welded?
@scottluna4249 Either the S&S flywheel or the Welded OEM is fine.
Just a budget thing is all it comes down to.
Hi Tommy Which flywheel for a 131 do you recommend and what stroke
I’m doing the 131 with the CR512 darkhorse manowar, evolution complete clutch I don’t do wheelies or stunts. I am known for doing hard down shift at time but not always
Use a 4.5 inch stroke flywheel. S&S Flywheel will be the best bet for longevity
If you’re runout is in spec, allowing you to switch to a gear drive cam chest, is it not going to eventually go over the amount of runout for the gear drive? Or does the gear drive prevent it? Love the channel. Always great content.
Yes the run out can change at any time no matter if it's a gear drive or chain drive. The recommended run out on gear drive cams is lower as the teeth have to mesh properly. If you happen to twist your crank (too much runout) then you may run into trouble with the teeth not meshing
@@MasterTechMiller Thanks for sharing the knowledge . Great channel.
Any runout north of .001" will shorten the lifespan of your lower end DRASTICALLY regardless of what "spec" or "acceptable tolerance" is in their garbage "book".
you mentioned downshifting,
so does rev matching while down shifting further damage this part? I almost always use engine breaking first to slow down. could you elaborate
Rev matching while down shifting is fine. Doing that greatly reduces stresses on the driveline.
If you downshift slowly & end up coasting along with the clutch pulled in & and the engine falling to idle speed & then downshift, letting the clutch out, resulting in a high amount of negative stress applied to the driveline, this will increase the risk of crankshaft runout
I’m getting a subtle but noticeable vibration on my M8 114. It feels like drive train….. like where the cruise control is set and the torque against the rear wheel is -0+. Down shifting or accelerating you don’t notice it but under a zero load I feel a rumbling vibration…. Very soft but it’s noticeable. Almost feel like I need to check my runout left and right to see if I’m having an issue…… I’m a throttle idiot😂
What is a big downshift for you? Because while I am cruising at 3rpm sometimes I downshift to engine break at the corners… btw I always try to rev match
I would consider a big downshift to be any RPM above 3000rpm without rev matching.
Coasting with the clutch pulled in & the engine at idle, then releasing the clutch without rev matching is also a bad idea
Speaking of the compensator, have you had many issues with the stock comp ramp? Would you recommend upgrading to a darkhorse or star billet? Thanks for the info Tommy 🤙🏽
The stock compensator ramp is rubbish! I highly recommend the billet steel upgraded one from Cycle-Rama.
The only time I suggest a dark horse man-o-war ramp is when a welded Flywheel & heavy duty aftermarket transmission is used.
@MasterTechMiller thank you sir. Always appreciated 🤙🏽
Great video explaining how it works, what increases wear and ways to increase strength for riding styles. Loved it thanks mate
Wow, something "stock" is rubbish? Say that isn't so? So....As a "Master" are you going to send your recommended "fix" or "redesign" to Harley-Davidson?
Also, I what do you do when you notice + .010" runout on a customer's flywheel assembly? Grab another one or do you attempt to fix it yourself? (Can't wait to hear THIS response)
@kennethwise7108 I'm not the one who is big noting about having a far superior design that waiting on a patent that is much better than the Harley engineering team.
You are what we call here in Australia a F#$k Witt.
The video outlines what options there are.
I believe the issue of run can be severely reduced by religious oil changes. Most bikers just do seasonal oil changes, I do twice a year.
That doesn’t even make sense. Has nothing to do with oil changes. Listen to the video again. He explains it so well
My question is, if you are doing performance upgrades, cams, tunes and so on, why aren't welded flywheels recommend to all those clients, I know a few blokes that have had massive engine failure due to this and to say the bikes are only fit for a purpose is a complete cop out! I hope Harley or the Toowoomba dealership honor's the repairs required to get said bikes back in a1 condition!
No young fella buying a breakout is just going to go touring on it are they??
Riding it hard or not, a 35k+ bike shouldn't just fail from a down shift or a burnout!
I think Harley Davidson has a lot to answer for on this one... even Indian do it better with forged 1 pce crank!
Budget. Not everyone can afford a welded crank.
What normally happens is the customer wants to do a stage 2 cam kit to get a better sound & a bit power from their bike.
When they discover just how much it improves the bike they then begin to start having fun with it, either by doing a few test n tune days at the strip or by doing skids.
It's a progression for most of them. I always recommend welded cranks to guys to who tell me they are wanting to give it a hard time.
If you wanna play, you have to pay. It's simple.
Those who tell me they just want to wake it up a bit with a stage 2 cam kit & don't want to spend the extra money on a welded crank then start mucking around racing etc will almost always run into trouble. No 'cop outs here'.
It's just like those 79 series Ute's. They go and buy a highly priced underpowered old tank and the moment you want to tow anything more than a loaded 6x4 box trailer you need to put a heavy duty clutch in it, exhaust, tune & snorkel just to get it to perform as it should by standards.
Harley have an outstanding warranty unmatched by any other manufacturer I know.
No one is stopping anyone from buying an Indian or going down that road with other manufacturers. People just want Harley's over other brands when it comes to big bore V Twin bikes.
Harley offer an unmatched warranty when it comes to performance & backing the products. 2 years, unlimited kilometres & almost everything is covered when it comes to performance upgrades. If people are out of the warranty period & depending on the circumstances Harley offer a good will warranty process available to them if they qualify.
There was a good post /article by a fellow James Russell I think his name is, ''Before you buy a Harley Davidson Motorcycle'' ,if you can find it on net ,about all the issues with the Twin cams etc and in his opinion only the Sportsters [certain years were any good ] fit for purpose by HD standards might be, ''only ridden on weekends and not flogged'' ,judging from the bad engineering /cheap short cuts to save time and money ,its just mind boggling the bad engineering and crank issues etc in this day and age ,realistically, if want a bike to ride hard ,flog ,buy a jap bike ,the only HD I will own, is a late model EVO after you learn their inherent problems and solve them [no big deal really ] with them ,you cant look at a HD and think its like a Jap bike.
So for those of us that do rev matched downshifts .. we are jacking up our cranks each time ?
How are we supposed to slow down?
Just let off and pull in the clutch at 2k and coast ? ?
I'm not sure how you came to that conclusion. Rev matching down shifts are absolutely fine. That's the best way to do it.
Not rev matching down shifts is what causes it
Hi Tommy, great video!! I always learn a lot from your explanations!! Thanks.
I had a question!? When you replace the pin with a solid steel one, wouldn't there be a problem with unbalancing the weight of the crankshaft? Or does it not affect the balance?
It doesn't effect it at all. The flywheels are not balanced to start with
🍻Tommy👍👊
Will a S&S flywheel hold up to popping the clutch and rolling burnouts and wheelies? And not twist?
@jackhorror6719 Much better than an OEM one yes!
@@MasterTechMiller so I shouldn’t have to worry about it twisting, even if I ride kinda hard without the plug being welded?
@@jackhorror6719 Yeah mate
approx. 2 yrs ago, I had a flywheel replaced with a "bullet proof" OEM Flywheel or my '15 HD limited. I have the original flywheel. How can I tell if that flywheel is not 100%? I was told one of the arms wasn't falling freely, but I cant seem to figure that out. It seems like it is falling freely. thanks..
How are you testing this?
@@MasterTechMillerI didn’t. The local shop tested it. I have the OEM flywheel in my garage. Is there a simple test I can do? I set the arms upward and one doesn’t fall down immediately, but if I were to slightly tap it, it does fall down.
I still can’t believe they can’t plug that shit from the factory… I mean come on.. how much would it cost per unit to give us a decent (not darkhorse quality of course but maybe SS crank quality) crank ?
If the flywheels twist doesn't that mean the outside crankshaft bearings are worn out. They should be holding the crankshaft in place.
I read lugging in too high a gear is also no good
Correct
The simple answer is, don't abuse your motor.
Yeah, sure you can strengthen your crankshaft, but all that will do, if you abuse your motor, is wreck your primary or gearbox or both.
You cant have it always.
better to buy a jap bike if you want to flog it
I don’t understand why wouldn’t S&Ss crank be welded? That makes no sense to me! If they are selling a better crank and rods why wouldn’t it be welded as well since that is the best way to go and they know that, how much more could it possible cost as a specific production part. Makes zero sense to me.
maybe a large crank pin[splined] and higher ft/lb to press together
It's because Harley is lazy. Look at an Indian Thunderstroke crank. It is still a single pin, but it's 5x stronger. The one and only reason Harley and Indian use single pin cranks, is for sound. Simple as that. Indian understood that the ancient "knife and fork" style single pin is incredibly weak, and it absolutely is, so Indian uses a crank pin that is like double the size of Harleys crank pin, and they offset the rods, but only just. Not offset like typical V configured automotive engines, where there's a significant gap between the rods and a balancer between them, but instead the rods sit right next to eachother and in fact, the rods ends ride against eachother as bearing surfaces. It maintains simplicity. It maintains sound. But it increases strength by an astronomical amount.
Help please ….. I have taken all of your awesome advice…. So need help again……my run out on a brand new bike.Has only 3 miles on it if that…. It has a 5thousand run out already.
They just started putting on a 131 kit for me
And now I’m thinking they need to fix the bottom end first. I’ve made them stop ✋🏻….. I trust your expertise!! What should I do? Fix it now ??? Or go with it putting in a 131 with CR 512 … romp will be changed and using the fueling oem cam plate like you do in your builds
I don’t do burn outs or wheelies etc
5thou is absolutely fine. Most bikes are between 3 and 6 straight out of the crate.
It'll be fine if you don't give it a hard time.
@@MasterTechMiller thank for all the advice
@@MasterTechMillerhaaa .003" Start saving up your money for a new mill. 😂