Doc, I am not a motor designer, but I am a mechanical engineer that designs and manufactures medical devices. In many cases these devices are polymers and we hold less than 0.001" tolerance. Even 0.003" TIR seems like a big number considering these are metal machined parts. Looking in from the outside, it presents that HD has relaxed tolerances to accommodate manufacturing, but the customer can end up with a less than ideal assembly. Great content! Thanks for posting.
Also, Indian uses gears on the drive side. This is the reason that Indian can Utilize a belt to the rear wheel, as HD does, but having 120 hp. If HD had 120 horse, the belt would blow up due to the poor run out from the crank. HDMC just makes very designed bikes. I have a 2014 SGS and I know what I am talking about. Care to correct me?
@@tommymonzon5824 I dont understand. Crank runout has nothing to do with the final drive belt. And yes, if kept at proper tension they will hold 120hp. But, not if all you do is hammer them. Mine has 40k miles and is holding fine but i dont abuse it.
@@tommymonzon5824 : ehm.....the HD rear drivebelt is not directly connected to the crank in any way. The crank is connected to the compensator, which in turn is connected by a chain to your gearbox. The gearbox is driving the rear wheel, so what you are saying makes no sense.
I had this issue on an "08 Dyna. The vibration was bad from day one and the dealer refused to consider anything was wrong, and the MOCO treated me even worse. Fast forward to 2019 and I am prepping the bike for a 2500 mile round trip ride to SD. I had the cam plate off to check the wear on the cam chain tensioners and noticed scoring on the pinion shaft and the bearing in the cam plate. Pinion runout was .021". The oil pump was pretty beat up, but hadn't failed probably because I really could ride it hard beyond about 2500 rpm or the bike would throw you off. Spline shaft side was .017" runout. I sent the bottom end to a nationally known and respected rebuilder and they found that the spline shaft had been machined .017" off axis, or off center if you like. This didn't happen due to me riding it hard or mis-treating it. Harley built it this way. $3000 later, I had a rebuild, trued, balanced, plugged and welded crank with less than .001" runout in the case with new upgraded bearings. New fueling oil pump, new fueling cam plate, and other parts, gaskets, and bolts. Runs like a dream now. Last Harley I will ever buy.
That can't be, you certainly must have abused your engine. The motor co would never have something like that pass their extremely high quality control standards. (Please insert as much sarcasm as humanly possible)
Harley keeps the tradition alive, of the owner having to fix ,and upgrade everything from the factory ! like a true ''Classic'' of yesteryear ,a True ''Enthusiast ''
Runout is what HD designs into their pinion shafts so you have the opportunity to purchase upgraded HD SE parts. Aftermarket suppliers also take advantage of this marketing scheme.
When the truness and play issues are off, its a chain reaction of everything is affected. If I have the cam removed from a shovel engine or an evo or a twin cam, plate and the two cams first thing I do is grab the shaft end and push and pull towards me for in and out play and then up and down play. If the play is excess, I then know its wasting time to go farther on any other repairs that involve outside of the cases. Here are some major things I never see checked when i watch videos of cylinders being removed, and that is back and forth play of the rod needle bearing, not slide play, but side to side play. I also never anyone take the cam or cams and insert in the case needle bearings and check to see if the move up and down or what would be side play, side play stands for tilting and up and down stands for exactly that. Dial indicators can show accuracry in round ness of a circumference and could show accuracy even in a shaft that had equal wear in the bearings, but have up and down play in the whole side to side assembly
One of your better videos in recent memory. More technical information and less selling! You have restored my faith! As for the information - really cool and better understanding of some of the forces in play when I'm riding my bike and the probably consequences of my, sometimes, behavior. Thanks and stay safe!
Yep that’s what happened to my 2004 decommissioned cop bike the oil pump failed and when Rodney measured the run out on my bike it was 7 hundredths If I remember right. Yes Harley did warranty my motor.
Probably 7 thousandths. .007”. ..., 7 hundredths .070 , is 70 thousandths, thats more than 1/16” which is .062” . But .007” is a LOT of runout and is likely the cause to be sure. If it was in fact .070” your flywheels had to have shifted.
Thank you Doc. Important topic. I may not fully understand the topic but it would seem that a better designed shaft and bearing in that bottom end might not be a bad thing.
Interesting.. yes you do have the experience here and You mention beyond .005 and that could do wear and damage such as the oil pump, but Harley seems to have changed the except able tolerance range to .012.. Those people with .006 - .012 run out can not install the much improved cam plate/oil pump combinations due to excessive runout.. but harley MoCo is still claiming it's good (?) I think you forgot to mention to be sure to grab the end of the crank and lift up and down to see if and how much you should add to your total Runout value.
I really like your videos doc because, they really help the rider/home mechanic be able to diagnose what is happening when strange things seem to be happening and also know what's needing to be done and in most cases it would need to go to a qualified mechanic to get the work done. Which is good to know, it's good to know when I myself or someone else can do the work at home. Or the bike needs to go to a qualified professional. Thanks again doc
My rd400 yamaha had a pressed crank. It made 55 hp. No problems. My 88 tc has 30k, it runs flawlessly and getting on 581 from 83 in pa. i like to twist this mf up to 5500. Ive worked on high performance jets, and ALL engines have limitations and operating envelopes. Burnouts and hard launches are gonna beat a big twin crank. And yes S S motors have problems even though the biggest engine they make are twin cams. Dont abuse your bikes engine and it will give you long service. Ive seen tc 88s with 85k and run beautiful. Leave the drag strip stuff to the race bikes.
@@aaronszymanski4589 I like it and plan on keeping it, hopefully, forever. That said, HD's engineering needs to get better. If something major goes wrong with my Superglide its gone and i'm getting something else.
@@genegeneish all true, provided the runout was close from the beginning. I’ve seen some of these so far out they’ve started destroying the oil pump from day one. The earlier 5 piece cranks could be trued back, the early ( 85 suffix) Evos had one side pressed in, then these. Throw away and replace.
My opinion, I support and believe in a well made flywheel for a performance designed motor. I would use gear driven cams in racing applications only. Especially if the motor still uses Factory roller bearings on motor drive sprocket side. There are reasons why there are chain driven cams…..Doc
@@LowCountryHarleyDavidson "There are reasons why there are chain driven cams." True statement. And ...those reasons are that the factory cheaped out on not-cheap motorcycles where they took their scalpels to them for reasons of lowering costs AND quality. No other "reason" exist, if it's no offense to you.
Another great video. Thanks. As others thought, this tear-down sure seems like an expensive way to measure run-out. And then with hopes you don't have to rebuild the flywheel/crank. My TC 103cc has 70k. I installed SE compensator. Same junk as OEM. Installing DarkHorse Comp this week. Then I'll ride this motor into the night. When it's tired, installing an S&S motor/bottom. They have corrected the weak links in an otherwise beautiful piece of machinery.
Big difference from shovels and pans. We always did them but I dont know if dealers did them. But then again they are rebuildable even if they were sometimes frustrating. I skipped evos all together and am learning my early twin cam. I havent checked the sprocket shaft but my pinion is just over .001 so good there. I will tear down when it gets hot next may and then i will check it. I dont run a auto tensioner and my sprocket bolt doesnt come loose so we will see. This is a great little nugget of info. Thank you.
Thank you for this video, so many of my questions answered and some I hadn't even thought to ask. Im preparing to install a cam at home and originally thought I'd just toss another chain drive cam in.... then thought I'd best get the tool to check runout. Well now I see that knowing could possibly save a motor... but then im thinking maybe best to just buy an aftermarket short block with all known issues addressed and my selected options installed? My stock m8 seems fine but as soon as I start measuring lord knows what I might find?
Received a used vance hines fuel pay, one of the old models. I installed it in my 2003 fatboy, fuel injection, mapped it. Rode well for about 5 minutes and almost didn't get back. Are those models of paks good for 1 bike only, the first bike that installed it?
Thank you Doc for all your informative videos. I’m going to upgrade the flywheel assy to an S&S due to my Turbo and upgrading the cams. I feel like the 2015 A motor with lefty bearings are okay and no Timken really necessary for around 130 hp/tq. I think the weak point is the crank and no the bearings. Am I correct with that assumption and would you do the same or upgrade to Timken? S&S feels my upgrades since I’m not one to abuse the bike is okay.
3 thou or under on a stock m8 crank from factory brand new is a good one lol After miles that shit just grows and grows .. I got a 124 in my 2023 road glide .. 18k miles .. 5k on the 124 I think …. Wondering how much runout there is on that thing by now .. ugh
None of this would be an issue had they not used those cheap crappy pressed together cranks in the Twinn Cam. EVO engines did not have this problem. They used bolt together cranks. S&S makes cranks for the Twin Cam that don't have this problem. I wouldn't buy a Twin Cam without expecting to spend a huge amount of money to rebuild it with S&S parts. But it would still be a better deal than a smoooooth M8.
Very good explanation.seems to me loose tolerances are your friend. Belt drive primary.is preferred. Mechanical oil pump needs to be changed to electric.transmission needs a slush box. Racing and reliability are two ends of the spectrum. But that isn't real news.
A compensator has a strong influence on flywheels. Timken set up is strong. There a too many things that can contribute to failure to blame one item. Thanks ~ Doc
Is it standard procedure for a Harley tech to check the pinion runout when installing a full cam chest kit for a Stage II build or must you request they do it?
No it is not standard procedure. If a seasoned tech has the time, they will. But most customers want their bike done ASAP, and the labor cost quoted does not include this procedure. Request it if this knowledge is important to you. Thanks ~ Doc
Hi Doc .I built a M8 117 stock motor and I installed the cam plate . Now the crank won't turn over by hand it won't budge. But when I loosen the cam plate screws the crank turns by hand . is that to much run out . I even took the cam out and the oil pump and the crank still gets stuck when I tighten the screws to spec .there must be something going on with the crank or a warped camplate.
I have learned that things rarely run out or wears out with religious oil changes. I change my oil twice a season on my cars and Harley-Davidson. Most engine/motor issues are due to wear so religious oil changes deal with all that in a nutshell. But if Harley-Davidson would do like Indian and many others and use gear drives in combination with all above a lot would be redundant. The old way of doing things is gone such as that dam chain drive primary.
The reason they don't use gear drive is flywheel pinion runout. Many are way over 003". You need less to go gear cams. Your whole post is incorrect because multi-piece crankshaft comes from the factory with run out, some excessive.
Nice instructions, clear and understandable 👍 I am astonished by the combined rod crankshaft design from Harley👍. My KTM has " metal dust " around the flywheel magnet side area . I'm suspecting runout. Isn't a press fit crankshaft adjustable to be true again?
Great info! I am was curious about your flywheel truing stand. What is the brand or was this something you made? Looks great for the earlier motors. Any info would be great. Thanks!
I have a question if you have any input I’d appreciate it! I’m doing 509c cams on my 02 flstc that was all original 20,000 miles on it. I ordered Screamin eagle cam plate went to do the conversion and noticed the original plate and front oil plate vane wearing grooves in each other No grooves on the pinion or bushing. Runout on the pinion side is .002 or two thousands. Witch is in spec. What would cause this to happen kind of curious before I put $1600 worth of parts in this engine. If you get time to respond I’d appreciate it! Thanks for your videos👍
Question hd flywheel I see people hit the flywheel s on the trueing stand won't it bent the outer smaller shaft maybe half thousand or so looks like bad thing too me
Has it always vibrated at this speed or is this a new development? Have you changed the exhaust in anyway? People do not realize the exhaust is a tuning fork. Change it and you create vibration. even removing a muffler for a tire change and sliding the muffler back on to far.....I always suggest if possible for you to ride another street and find what is "normal" vibration...Doc
What do you do if the Flywheel's have more than 5 thousandst run out ? Trade them in for new , wheels , rod's and pistons and shafts? Or make ash trays ?
Even though I'm a Harley owner, I'm wondering why we keep buying motorcycles that even require us to worry about that runout measurement on a "premium" motorcycle. I have never seen anyone explaining the importance of runout on any other brand of bike. I suspect Harley has us pretty conditioned after selling bikes for over 100 years. Just sayin'.
@LowCountryHarleyDavidson I had my runout checked cam side .0055 bad but bad enough to justify the cost of repair? If I'm going in there, I'm going to put in a stroker crank, 05 RK
Do not buy a big twin Harley past 2002 that's is when they started pressing the flywheels together and using roller bearings instead of truing the flywheels by hand and using the timken bearings, a bottom end that lasted for over 200,000 miles changed just to save on cost. I own a 1986 FXST I restored the bike back in 2003 bought it used in 1995. split the cases the timken bearing were like new after several thousands of miles, put it back together with a new refreshed top end and ride it everywhere it will out last me. My 2017 ultra limited I guess I will have to roll the dice on that one because of comfort for me and my wife I have to sacrifice flywheel runout and hope like hell it doesn't get worse. Thanks Harley Davidson you bastards.
You did not have to call names. Yes the industry has changed. Mr Bryce has shared several times that the now roller bearings are good enough with less drag. I personally like Timken. If you want your modern HD to follow the tried and “true” way. There are several companies that can convert your motor…..Doc
Wow dealers have no provision to correct flywheel runout? Guess I will go to a unauthorized harley machine shop and get it corrected screw the warranty
So after a hundred years Harley decides to redesign a part, so now even a Harley dealership can't fix, great idea, lets make a part that can't be fixed, it needs to be replaced. If anyone associated with Harley Davidson Corp. wonders why they can't retain loyal customers, this might be a little hint. I personally wouldn't own a Harley Davidson product built after the last EVO rolled off the production line. You are now making $30,000 throw away bikes. Sorry Doc, I love your channel, but I hate the company.
Meh.. But I have seen the horrible brake lines, The atrocious engineering of their electrical systems and the asinine way in which they funnel their fuel systems on old carb units. How do I know? I own a GS850GX. OEM even calls for valve shim adjust every 5k. That'll cost you $600-800 a pop. I'll take my 103cc Harley everyday. 70k miles. Love them all. Face it, if it's got wheels or tits, you're gonna have problems.
You forgot to tell them when harley had a big problems with .007 run out for 3 years, thats all I want say, I don't want to alarm people with what years.
In the end Harley is incapable of building a motor that doesn't have serious engineering flaws, and thinks it's acceptable to pass along the cost to fix the engineering mistakes on to their customer base. Every singe Harley motor has serious expensive engineering mistakes built right in for your enjoyment. Its like a Cracker Jack engine, it's a surprise what will happen and what it will cost lol I think from here on out I will build my own motor with quality components to get a reliable Harley....at least I will know what the cost will be.
@@dukeljk2191 yes you are....all you have to do is a quick search on the Harley forums to see what customers have to say, every single engine has a design flaw built into it....every one right on up to the new M8's
exactly last 2018 cvo puking out oil .... traded that in for 2020 road glide and now my run out is 6 thousands .... was thinking of doing a 128 but guy wouldn't would only do a 468 cam. I was out at the lone star rally. Been thinking she was't running right so i let one of the shops look at out there. lifter was nasty looking. IDk im sick of wasting more and more damn money. now either i have to do a bottom end or what sell and buy a pursuit indian. so tired of this with Harley and ive been HD owner for 15 years. I dont ride them crazy.
@@ashebarley77385 indian has some issues to, but if yiou do your research you can avoid most of it, same as with harley. You just cant jump on them and expect things to not happen like a lot of folks think.
Yeah Doc, tell the MoCo how their current designs suck: pressed cranks, no timken lefty bearing, and the automatic primary chain tensioner. All add to runout. MoCo sucks.
I appreciate your post and thoughts. But tune into George Bryce Star Racing videos to learn he builds and drag races with the MoCo pressed cranks, no Timken ( he calls them Trailer bearings),auto tensioners and does fine…Doc
