I'm sorry but I do not agree with the theory that the back cylinder hydro locked causing the failure as shown. My reasoning is really quite simple. 1. You stated that the engine inexplicably locked up without warning. In order for the amount of oil required to lock up the rear cylinder to accumulate a number of things would have given you warning but the most relevant would be the spark plug fouling with oil and ceasing to fire. You said no warning and I would consider that a warning. Unfortunately you did not indicate whether the rear exhaust pipe and exhaust port had any accumulation of oil present so I am assuming that this was not noted or in fact present. 2. If the rear cylinder had hydro locked, the rear rod would have been destroyed and probably round housed the case when it bent and broke. The video clearly shows the rod to be in pretty fair condition and in fact turning freely on the crank pin. 3. The rear piston and head show no signs of there being any hydro lock damage yet there was oil present during disassembly. Hydro lock this severe would normally cause some damage to the piston and quite possibly stretch the cylinder studs to the breaking point yet there is no evidence of this. 4. Was the motor on it's side at any point in time prior to the tear down? If so, this could be the reason for the presence of oil as it leaked past the rings from the bottom end while on its side. 5. When you pulled the cam out I noticed there was only one washer behind it. Where is the second washer with the locating tabs that should have been behind that against the pinion case? Was it present and you neglected to show it or was it in fact not present at all? Could be the possible source of the metal shards if it disintegrated. And then there is the matter of the missing washer on the timed breather cylinder of the oil pump and the shavings on the cylinder itself. Again, missing or disintegrated? 6. In the video, you did not open up the oil pump pressure side and examine it for shards or the possibility of it being siezed or having failed other than when you removed the cover on the scavenging side of the pump which contained oil. Another critical telltale would be the presence of debris in the pressure relief valve located on the top of the pump pressure side. If debris had lodged in the relief valve it could prevent it from closing fully which in turn would cause possible oil starvation. Roller bearing bottom ends do not produce a great deal of oil pressure but do require a tremendous flow to keep the rollers cool and lubricated. SInce the contact points on roller bearing engines are so small in comparison to shell bearing motors any lack of oil or any contamination will have disastrous effects on the bearings themselves causing them to flat spot and sieze. 7. After you split the cases there is a great deal of evidence that what infact caused this failure was oil that was contaminated with metal shards that entered the outer timken bearing causing it to seize and break the crank pin. It is quite apparent that something, either the breather washer or the missing cam washer did in fact disintegrate which in turn supplied the medium for the bearings failure. You yourself stated that the outer bearing fell apart when the case was pressed off. Another telltale is the fact that the output side of the case was cracked which would seem to support the theory that the timkens failed and the crank flexed enough to contact the case or some shrapnel was lodged between the wheel and the case immediately prior to failure. Another thing that would indicate bearing failure is the fact that the left side of the crank was forced out of alignment and wedged tight to the case. Since a Timken is a tapered bearing as it failed it would tend to pull the crank in the direction of the bearing that was failing. Had it been the inner timken, the crank would have forced towards the pinion case but the end result would have been pretty much the same. If I was a betting man I would say that one or both of the missing washers disintegrated due to a lack of oil or excess clearance due to wear and tear. They in turn entered the oil system which in turn siezed the rollers in the outer bearing causing catastrophic failure and the weakest part of the crank being the crank pin failed under the excessive load. I have seen two engines that suffered hydro lock over the years and in both cases the rod bent and gave way. (One was a boat that sank while running and the other was a severely cracked head that allowed the coolant to enter the cylinder via the intake port.) Since there is no evidence of rod failure or in fact any bending or rod bearing failure, nor at any point did the rear cylinder stop firing due to the presence of excess oil and subsequent fouling, I cannot support the theory of a hydro lock. Just my observations based on past experience with other motors.

This is the way I wish all social media worked. You made an earnest effort to find out what went wrong and invited knowledgeable folks to offer up advice, which they did, and without flaming or copy/pasting what they can find on a quick Google. Glad you came out OK with the lock up.

Thanks Lee and all your volunteer detectives. Fascinating video. I have done enough work on my bikes to know that I need more knowledge. Watched and learned !

Thanks to you for posting this and to Mr Norman May for his excellent post, I have no doubt a lot of people like me will have learned from seeing this and appreciate it as much as I do. I hope your work pays off and wish you loads of trouble free miles in riding in the confidence that you fixed it yourself and now really know your bike.

Thank you for your video. By making this video you helped me figure out why my motor locked up. Parts are on order, and she should be up and running in a few weeks. Thanks again

You know when you do videos like this it feels like I am in your garage with ya! The way you filmed it is great!

Thank you ! Its quite the honor to look over the shoulder of a master !!!

I'm glad that you made it out safe. I have a difficult time trusting anyone to work on anything of mine. I hope you got her back together successfully.

Great challenge, I have never gone past the top end and never thought I could trust myself to do a lower end. Maybe this will be on my bucket list.

From what I've seen and heard, that shop owes you a new engine.

A Big Thumb's Up From Kip Hayes in Macon, Ga. Lee .......what ever caused it, i hope you discover it.......the video is worth it all....... sorry for your loss of the engine .......but the presentation to a layman was second to none!!! I Thank YOU!!!

Great video i myself am a backyard mechanic have worked on dozens of bikes i own a 1999 evo and have a 106,000 on her with no problems it doesn't even smoke or k nock yet a little noise comi g out of the rockers but not serious i believe you diagnosed this correctly and to be honest i have never seen a crank pin break they are very tough hope you got your bike back up thanks for sharing

Well Lee, I can tell you this, you're 10 times the mechanic that I am! LOL! Seriously, that is something I'm really not good at! We all have our gifts, being a mechanic isn't one of mine! Kudos to you brother!

This vid has almost made it to 700 comments !! Awesome vid and great comments from many of you !!! That’s why I love KZfaq !! And that’s why I love this awesome universe with all you awesome Kool bikers that always points me in the positive direction of fixing my bikes when parts fail !!

Absolute pleasure watching a craftsman at work most interesting.

Great video. I've done rebuilds on my '79 Shovelhead. I don't do much more than change the oil on my '06 Twin Cam. Thanks!

Someone get this man an impact wrench! In all seriousness good video, and it looks like you have some answers. Best of luck.

Glad you're alive🙏🏻

Great Harley engine tear down video. My lowrider S is currently in the shop for a bottom end knocking noise. It has a 110 with approximately 7,000 miles. After confirming there was a knock, Harley approved a tear down. They found the flywheel gear binding. Master tech said if left alone the bearing would have developed flat spot and a chain of events leading to other engine damage. Good luck on your rebuild, I wanted to share this even though it may not be related to your engine locking up. Best regards.

Good information about grabbing the clutch

you say Harley shop. if you're talking about a licensed dealership take them to small claims court. they will not want Milwaukee to know they screwed up and that should change their mind about fixing it. that's exactly what I did and I got my motor fixed.

I agree with Norman, I have seen lots of hydro lock ups it bends the rod , because its the easiest thing to bend or break. I spent 34 years at the RR and I was a mechanic on the diesels.

Congratulations on 68k views. I remember when you made this one. Great job Lee.

Very informative and you are much cooler than me over such a blown-engine,,, I'll stay with 2T 250cc dirt bikes after seeing that tear-down,, Good luck with your bike!

Crankshaft end play set too tight, same thing happened to me on my 46 Flathead, doing 55mph and it felt like I was putting the brakes on, pulled the clutch in and pulled over, she was locked up! I tore it down and rebuilt it, I used the original crank shaft spacer to get the end play, started to bolt the cases together and the crank wouldn't move, re-shimed for proper end play. That's is all it was, luckily no internal damage whatsoever.

Bit late to the party but in my opinion, 'beating flat rate' caused the problem. Your not supposed to use an 'air gun' to remove compensating sprocket nut but it's faster and cheaper than doing it right plus rarely actually does cause a problem. The bolt up cranks can easily get twisted causing pretty bad imbalance which flexes shafts in a different plane. Vibration may have seemed normal but even if you only revved it once to 5K it could be enough to snap pin. (I've done a LOT of HD 3 and 5 piece cranks) Personally I would be interested to see wear pattern on crank pin , main shafts and bearings, it tells you a lot if you know what to look for. Hydro-lock would have caused a totally different type of damage

That sucks but glad your still above ground. Great tear down and good catch on that other cylinder I thought for shure she was going over. Well hope to see you out there in the wind soon Remember this time warm - ups and Oil changes Ralph.

Please note, I Iive in Australia and years ago I had a BMW R80/7 that locked up on me at 60 mph some 950 miles from home, a long story short the BMW mechanic told me that one of the bolts that hold the conrod onto the crankshaft snapped in two! It happened so quickly and suddenly that I hardly had time to pull the clutch in given that the back wheel completely locked up also,of course BMW tried to blame myself due to lack of engine oil etc, but the bike was serviced by them 2 weeks prior to the engine lock up and BMW did not charge me for any of the repairs Great video by the way! Regards Alan Reilly

Nice video,Thank you for sharing!!

Looks like the shop that changed your state put the washer on the wrong side of the rotor. When they overturned the comp nut it drove in on the sprocket shaft (timken) bearing. When it heated up it expanded and locked it up. When your guy droped the case it freed it up. Oh and he cracked your case half on the press.

this was awesome, easy to work on when pulled from the bike. 🦁👍👍👍👍👍

Hi just watched your vlog, really good tear down. Just bought my Fatboy Lo Special (Ist HD) new for my 60th birthday , I would never have been able to do that job --- even with the factory manual. Sadly for you the dealership treated you badly, you would think HD would sort these robbers out, bit here in Wales there are stories like yours. Good luck with your new engine & many thanks for such a good vlog 🖒😎

Hi Lee you did a great job on the tear down, I hope you are able to get your ride on the road again soon..... I am totally sure the dealer screwed up big and you paid for it. This video reminds me that I can not really trust the dealers for squat..... jp

the" screw" you pulled out at the stater, that was a screw for a cabinet door hinge mount!

great video,looks like you know a bit of engines i just take them slowly apart and put every piece and place it on the table and when i put it back together i go in the reverse direction ,I'm not a mechanic either but this method seems to work for me when i see something that's broken i replace it great tutorial Lee

Well brother this was an excellent video. A lot of good information here on how to tear down this engine. Not knowing a whole lot about motorcycle engines I would tend to agree with you though about the Hydro lock. And if it was me I think I would go with a new engine for sure. Thanks for sharing my friend.

I'd have to ask but if that work involved re-building the top end it's possible that they didn't give enough clearance to piston - cylinder. That scoring looks like the piston seized when hot and then loosened up after the motor cooled down. If it were rod bearings there'd be more metal in the oil and it would be obvious when looking turning over the motor with cylinders removed. You'd hear the metal on metal. Just one persons opinion.

I've been working on H-D's for 33 years professionally in shops. It's a faulty crankpin that broke and took out your engine. That's certainly not the first one I've seen like that. Everyone I've seen breaks through the oil passage, just like yours.

ABSOLUTELY RIVETING (n.p.i.) vid to watch, for this soon-to-be Newbie rider, Lee! I've never seen a mc engine torn apart from top down to its bones...and have wanted to for a LONG time! AWESOME "mc engines, 101" educational film, Sir - MANY THANKS! :)

Very nice teardown video. Looks like it's engine time.

Hi Lee. Sorry you had this failure. As a Caterpillar engine mechanic, I've been through failure analysis training. If I were you, I would look closely at the broken ends of the crankpin. I have a feeling that the crankpin fractured first (for some reason) leading to the flywheels no longer being supported. That let them move freely and at angles, cutting into the case. This caused the aluminum shavings and ultimately caused the lockup of the engine when the flywheels jammed against the case halves. By looking closely at the fracture face of the crankpin, a good failure analysis technician could tell if that breakage was caused by one huge hit, or if it was a crack that grew slowly until it broke (thousands of miles), or a crack that happened rapidly (minutes). I believe the clues you need are in the crankpin area.....

5 weeks in the shop having work done on it and then locks up at 70 mph......... Nice.

Great video. I am the only person who has wrenched on my 05 Sporty since I bought it new. At 80K it has only needed a CKP. It has been a very reliable bike. Any other work has been modifications. I hate to have anyone work on my machinery. I may be slower but I get it right. The factory manual is your friend :) Good luck with whatever motor choice you make to get your bike back on the road.

Very cool 97k views by 11.26.2017. Great work Lee.

give tatro machine a call, keenan may be able to shed some light on it and if you were looking to rebuild it im pretty sure he can do it and make it 10times better/ more reliable than stock

Could be crank pin failure. Every rebuild I did, I would test the crank pins on a Rockwell Hardness tester. Its been awhile but I believe the crankpin would fall between 58-62 on the tester. New parts do fail. Would also die check the con rods for issues. I did see camshafts snap in half. Also, how was the endplay on the sprocket shaft or the conditions of the timekins? All in all, if it was a bearing failure I believe the motor would have just slowed down to a seize and I agreed with Scooter Tramp, it wasn't hydro-lock. I'm going with crankpin failure....

Thanks for sharing , hope things worked out for you .it's a shame , crooked people in the motorcycle industry. The mechanic , doing crooked work , and now the engine lockup , you should expose the shop that did it . Thank for the heads up on using the clutch , in a lockup

The difficulty from this point on is the possibility of micro fractures in the various castings and forgings. Of course, the hardware items were subjected to a severe shock, and the resultant wear on the threaded component surfaces may add to the deformation of the engine as a whole entity. With this being said, the decision to replace the motor entirely is wise.

Fascinating, watching someone working on an old farm tractor engine.

Not personally taking the engine apart leaves a lot of room for speculation, but I believe the crankshaft broke causing the lockup. The crank pin appears to be broken at an angle. Thus the pin would put pressure on the flyweights forcing them away from each other. This would cause; 1) the flyweights to be pushed into the inside of the crankcase wedging the halves inside the cases and ultimately locking up. 2) the broken crank pin would cause the alternator rotor to be thrown out of alignment allowing the rotor to run against the head of the damaged screw (no fault of the shop that installed the stator). My conclusion is: the crank failed due to metal fatigue caused by vibration and/or imbalance. The crank failure would be the source of the metal filings. Although the engine 'locked up', it was not immediate and the crankshaft rotated many times before coming to a stop. I propose that if the engine had been turned opposite it's normal direction of rotation, the engine may have been 'unlocked' and the broken crankshaft may have been obvious without complete disassembly. Glaring mistake made during disassembly; the pinion gear, oil pump drive gear and associated parts should have been removed from the right end of the crankshaft before attempting to remove the right crankcase. I agree with Fred, the case was broken when the shop pressed on the crank. I am a mechanic with over 40 years of experience.

I liked the video; enjoyed it. Liked and subbed, great content !

Every one can learn here out of this useful striping video and specially from Normans May analysis

Every time you produced a paper bag I expected a magic trick. I've always had European or Japanese bikes. I got the chance to ride an 883 for about 1000 miles around Arizona. It vibrated so much when you had something in your mirror it looked like you were being chased by a herd of angry cars!

Lee the rest of the bike looks great . A new S&S would be a good choice , in dependability and time. Look forward to seeing where it ends up. Yes it's a lot of cash . Liked the teardown and I wished I knew more. Cheers buddy.

I also agree the hydro lock theory would have caused noticeable decrease in power with the eventual destruction of the rod. The failure of the main bearing is a much more likely candidate. I've never worked on a Harley before so I found this a very interesting video, i'm a Triumph fanatic. It's always a bad feeling when you're looking when you're looking at broken cases, good luck with getting it back up together.

Great video ! Congrats!

I don't think a Hydrolock was the culprit. You would have seen nothing but oil smoke for some time before locking up. Looking at the casings there appears to be a half circle indent on the thrust face of one casing possibly caused by a loose washer lodging there and jamming. There is also damage to the thrust face which would explain the shavings found throughout the bottom end. My theory is the "missing" washer highlighted earlier found its way to the back of the motor and seized the engine up. The bent screw could have been caused by the ensuing mayhem post lockup, as with the cracked casing. Incorrect assembly at The Harley Shop is my call on what caused the failure. Cheers Ric

That Harley shop should give you a new EVO motor, or equivalent, with their sincerest apologies.

I had a sprocket that came off the gearbox output at 80 mph, back wheel locked up solid and it took a lot to keep the bike upright and steer to the side of a fast moving road. It ain't funny when you get a failure! From my two stroke days I always ride with the clutch covered!

For those more experienced than I am, it almost looked to me like the main seal wasn’t installed correctly. I don’t see any spring on the seal showing that if this was chain drive, it would allow oil from the engine into the primary, drying the engine out and filling the primary. If you run chain drive, aren’t you supposed to install the main seal with the spring outward toward the primary, and facing in if you’re running a belt drive/dry clutch?

The Caterpillar Mechanic may have nailed or closely nailed the failure. However, My thoughts. If it had been a hydro lock, the connecting rod, wrist pin, and piston pin bore are significantly weaker than the Crank and would have shown some kind of pressure damage. Not limited to but including piston pin bending. That being said, with metal shavings in the engine tell much. The crank was not mounted securely and it was allowed to flex causing metal shaving. Over time, that movement would have been amplified on the large end of the rod, and a micro fracture would result that eventually would give. From the pictures, the metal fragments throughout the engine, indicate this was not a quick catastrophic failure like a hydro lock, but a slower process allowing for all the metal shavings. Without physically inspecting, this is just a guess. One more thought. The Large rod end on the crank is significantly stronger than the hollow piston pin. The Large end has enough strength to easily shear the small end piston pin and not even see damage to Crank journal. If the crank was securely mounted, everything perfect, no metal fragments, I would guess in a hydro lock up, the Piston pin would shear, the pushrod would punch through the piston crown.

You stated the shop improperly installed bent screw behind the stator. I would like to know what shop!

Awesome video. Thank you!!!

This appears on my recommendations since weeks. Now that I opened it finally I hope youtube is being satisfied at last and stops recommending it to me.

Not a hydro lock, the oil would just get pushed out the exhaust causing it to smoke and pour oil out of the pipe. Also if it was leaking in that much it probably would have fouled the plug and it would have been down on one cylinder. Problem seems to be some where else. Great tear down job.

You've already got the suspected failure from Norman May, so I wont get into that, except to say what little metal shavings that are there, isn't enough to equal the bearing material and the missing washers (that all looks like bearing material). Did they happen to disassemble that side of the case when they did your motor work? I betting they left them out! As for your dilemma, the first question is, do you want to keep the bike or sell it? If selling it, you could get a used motor (that is a runner) and slide it in to get the bike sold. If you plan on keeping the bike, and you've already admitted you're not really a mechanic, do you seriously want the headache of a rebuild? If yes, then good luck, or at least have somebody knowledgeable help you do it. If not, then bite the bullet and get you an S&S for two reasons, S&S don't build junk, it'll be a righteous build with a spec sheet from it's testing and it'll come with a warranty (you certainly wont have either of those when you rebuild it yourself). Besides, an S&S on that year of bike would give it a bit more value, than the stock motor would, if you did eventually sell it. Though, I would suggest riding it like you stole it for a bit (it's an S&S, it can take it), to get some of your value out of it first before you sell it. Oh, and one other thing (as if this even needs mentioning), don't take anymore bikes to the chucklefucks that did that to your motor. Find somebody else that will appreciate your business and treat you righteous, there is just no excuse what so ever for shitty workmanship like that!

When you split the cases, did they just fall apart? I am curious as I have never opened up a Harley motor, and am in the process of disassembling a 96 Evo that was in a garage fire....with the intent of reusing what appear to be good cases.

Good Luck, great video.

I don't agree with the hydrolock theory. Hydrolock with oil does not happen when an engine is running. Hydrolock due to oil leaks from overhead would have occured after the engine stopped and would not have allowed it to even start the next time. There is simply not enough time for that much oil to get into the cylinder at the RPM it would have been turning at 70 mph. That much oil getting into either cylinder would have also caused a running engine to emit a smoke screen of epic proportions.

I have not had a lock up. But, I've had a "back tire (luckily)" deflate (punctured), and going high speed down the highway, and having horsetail wagging and the inner tube is coming out and attempting to grab inside the chain, and rip the tire off the rim. Then getting off the highway to the (luckily) nearest motorcycle shop, and have a new tire installed. That was scary enough.

Norman is on top of it... without doubt. May I add info that may be of interest to all of us that pay top dollar for these machines? This "timed breather" that Norman speaks of,, is a cylinder with ports cut in it. It rotates inside of a fixed pipe with ports to match. The breather is made of PLASTIC !!! In my '97 soft tail and others I imagine. A plastic gear tooth broke away and found its way to the oil pump... the pump drive sheared as a result ! I caught the oil pressure light in time to save major damage. I raised some dust in the Longview, Tx. Harley shop when to my amazement... the replacement part was also PLASTIC !

Great video and awesome comment section. will watch and read again. I am going to be tearing my bike down and re-doing it. It's time. She needs a few things.

I think it would be helpful if you mentioned exactly what work they did on it on the shop. You just said "some work" which doesn't give any clue to whether that could have anything to do with the lock up at all. In the video you mention that they replace the stator. That should normally not cause anything like this unless they used force or violence on the shaft like hammer on it. One hypothesis could simply be that the lower crank pin just broke from fatigue and that's the reason for locking up. I can't see anything in there that would make things come to a halt fast enough to crack the crank pin. It would require a hydrolock or a severe mechanical like a cracked piston or broken connecting rod. A seized roller bearing like on the crank will likely never cause a dead stop that would crack the pin. My guess is that the missing washer which is grinded to metal debris is a misleading clue. I think there is a good chance that the crank, which is pretty delicate compared to other big V-twins broke from fatigue causing the lock up, and of course the cracked crank case as a result. I have seen too many clues leading the assumptions in my days to run after them, so I just boil it down to a locked up motor. The reason for it to be locked is that the crank big end pin is broken. All visual damage to the case is the result of that and there are no obvious reasons for the motor to have locked up causing the cracked big end pin so I can just state that it did happen.

Not possible for a hydro-lock, unless the valves both stick shut. In that case, there is no way for the oil to enter. I am guessing someone tried to free the motor by adding the oil through the spark plug hole, or the motor was left in a position for the oil to migrate into the cylinder. I'm thinking something happened to the left side crankshaft where the stator lives. If something hits that shaft dead on the end, it could have enough leverage the tweak the flywheels out of true. In that case, normal use would eventually destroy the crank pin. It's a surprisingly weak setup to start with, and if you add a bonehead tech into the equation, you can have a catastrophic outcome. That's one reason you never use any kind of puller on the stator that relies on the crank for a fulcrum. Yea, I know. The genius mechanic your friend knows said it's fine to use a puller, but then again, it's not his motor. You might inquire about the shop practice for removing and re-installing the huge nut on the end of the shaft that holds the compensator and rotor in place. If they use an air tool it can do damage if the air pressure is set too high. And BTW, the damage to the alternator wire cleat and screws was done when the crank broke and let the rotor spin out of true. That wasn't done by a boneheaded tech. Lifetime rider and bike mechanic here. Went to Harley school all over the country and have all the badges and class pictures to prove it. Worked at Collier HD in Roanoke Rapids NC for over 12 years officially. Several more unofficially. You get the drift. I'm not just a shade tree blockhead throwing darts. I probably could pinpoint the problem right off if I was doing this hands on. Like this it's a tough call. Good luck pard.

Dang good video. Thanks for showing it.

i also have a 92 softail evo 78000 on it still runs strong its sad what happend to yours! could have been the missing washer! but who knows any way evos are the best motors harley has ever built i also have a buddy that has over 100.000 miles on his evo and still runs like a champ hard to kill a evo i think yours was just a fluke! i will never get rid of my softail!!! thanks for the vid!!!

J B weld it, and put back together! thats probably how the shop would've done it and charged you for it!

Lee Ralph, I'm not a Harley guy, but I am an aircraft engineer and a biker who works on my own engines. I have several observations: The Harley shop let you down badly. There seems to be no reason for the bent stator screw other than bad workmanship. Please correct me if I'm wrong, and that seizure could have in any way contributed. The missing washer appears to be further evidence of same. What you describe as "shavings" really need to be analysed. If they were machining swarf, then that's serious negligence on someone's part. If they could be the remains of the washer, that needs to be established. It too is serious negligence on someone's part. We can all forget washers, drop parts, and stop/restart jobs and forget where we were up to, but due diligence is called for. You possibly have a case against the Harley shop, but your evidence gathering and recording is sadly rather too sketchy to constitute actual proof or stand up as evidence. Probably wouldn't hold up in court. Any lawyer is going to tell you you should have got the investigative work done by a trained mechanic - probably having given the original Harley shop fuck-ups the opportunity to correct their bad work. Water under bridge. You were also heavily let down by whoever did the pressing work. If you drop a customer's parts and damage them beyond repair you're liable. Period. My final conclusion is a two part one that firstly notes the highly inappropriate and ultimately comically ironic use of 'Evolution' as the name for this agricultural piece of ironmongery. The second part is to point out that it's clearly not a very good design. The amount of torque inside that motor is capable of shearing a 1" plus diameter shaft, but they didn't mitigate against poor workmanship, or whatever the apparently reasonably simple cause was. We know it wasn't visible catastrophic failure of a part. Engine design all over the world (except the USA it seems) has gone through genuine evolution during the years since this design was new. Having said that, I prefer flatheads/panheads/side valves to those things, and still think Harley engines sound better than any of their imitators. But they're unreliable tractors that I really wouldn't want to ride any distance. And to me, that's what bikes should be capable of doing, not just posing and brooding at the lights in leather vests, cut-offs and doggy bowls. I guess the final lesson is that you can't trust anyone these days, and that's sad. If I make a mistake, I call myself the appropriate name and admit my error. Long list available to anyone genuinely interested ;)

good video Lee. . . sorry to hear the news though. There has been good wisdom put forward. If I may add some from my own experience. Looking at that cracked case, sure looks like something jammed between it and the flywheel. Is there lots of scraping wear on the soft aluminium case? How could it get there? . . all too easy! I have dropped things into motors over the years, piston clips and steel washers come to mind!!

Thank You for doing a serious video, I am totally helpless with engines, and I rather watch others. Best wh. from Sweden.

with that much oil in the cylinder you would have had one heck of a cloud behind you. id bet the shop used a impact on the stater. if the bearings locked you would think they would have spun for at least a second. doesn't look like a rotary break on the crank pin. you might want to presume them damaging your bike if you haven't.

I'll tell you what, your crack case is caused when the big End Rod let go it's swung down and hit the counter weight which forced the other half of the crank to push out and cracking your case. you can see the mark on the other half where the pin hit . All the hydro locks that I've ever seen always had a bent rod or piston damage. which I never saw your piston but the rod looked okay. It could just be that the big end pin shared from being out of alignment. In other words the two halves of the crank are no longer clocked the same. That's what I think happened. I seen it a couple of times when something happened to the bike which jolted the motor. Since the big end pen are pressed into the crank, they will twist out of alignment and eventually something breaks.

nice to see quality tools

Sounds like a good weekend.

my evo did the same thing we found out the oil pump went out it was cheaper to buy a s+s motor than a rebuild im much happier with the s+s

Nevertheless, if there had been some lock up in the timing chest, I would expect to see significant damage. Probably many gear teeth stripped etc. The fact that a couple of square inches of steel crank pin sheared means that something even stronger than that caused the damage. There is nothing in the timing chest remotely strong enough to do that. Therefore I still think that the crank pin must have been significantly weaker than expected. Someone else mentioned looking at the broken face of the crank pin, probably with a microscope. To a trained eye (not mine), evidence of prior cracking or fatigue should be easy to spot.

Now after watching your other videos...I have to ask...did you have the work done at the Topeka Harley Davidson?

Good video! Good thing you were not seriously hurt.

Jeez, its like watching someone dissect an engine from WW1. Oh yeah, that's just what it is!

Crap! Glad you survived. Time to sue that shop!!

Great Video as I like to watch Motor dissassembly. whatever the cause of that locked up, put it aside as he sincerely said he is not a Trained Motorcycle Mechanic.

im not a motorcycle Mechanic ..but i do work on small engines for a living ..Let me just say everything has a reason for being in the motor .so ill have to agree with Norman on this one . when dude said missing spacer one that one shaft .it immediately perked my ears .

I wonder if this type engine could be used on a home built aircraft

The Evo is not a “true” dry sump there’s always going to be 3/4 of a quart of oil or so on the bottom. So it’s not a fluid void nor fluid pressure loss. There’s a bigger piece/chunk of metal somewhere (not shown) & probably wedge shaped...somehow got stuck between one of those flywheels & the case...The shavings alone are just not enough to do it. Once the crankpin broke all bets were off & those flywheels smashed into the case and ruined the bottom-end entirely...

hi lee, after watching your video on why this eng locked up, i think you are correct about the hyd lock.. as you know fluids will not compress & something has to break.. now what do you think caused the oil to enter the cyl? a lot of times when this happens, the piston will shove the oil out thru the exhaust valve, unless the oil was too excessive. do you think the oil pumps timing was not set correctly??

I wish you had shown a close up of the fracture surfaces on the pin. From a distance it looks like a brittle failure, but cannot be certain without a close up. If it is a brittle failure, look for the starting position, a scratch, or crack. Then there will be beach front type waves where the crack progressed. These are called Lueder's lines. They progress until you have a rupture type failure of the remaining material. The signature is quite unique and definitive. We were involved in a failure of crank in a diesel harvester many years ago that cracked the crank. Root cause was improper heat treat of the crank. Don't know if this is it... just another thought.

The Harley shop did a bad job. Good tear down.

My thoughts is, during the shop doing the repairs may have hit the crank in a effort to remove the flywheel. All it takes is a hair line fracture.

Great video

I always found old fishing tackle boxes great for keeping parts straight. Labels help as well. This brings back a lot of memories. That stator plug screw looked a lot like a sheet metal screw.. Not really a fan of the hydro-lock theory. If the motor was laid on its side it would let oil past the rings. Was the rear cylinder head filled with Oil? That motor was rebuilt in the past, so who knows what when on. Did you do a real close look at the timken bearing on the drive side? was there a spacer in there? I know it is a lot of questions, but I have been curious about this for a while. I hope you do an update, Lee, and let us know what is going on.