Why Did Engine Knock? I've never Seen This Before. Can We Fix It?
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- Опубликовано: 16 дек 2023
- I was given this 13 hp honda clone engine for free to use on a go kart build but the more we ran it the louder it got. lets tear it down and see what happened, i've never seen this happen before.
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during disassembly mustie says "just in case I end up putting it back together" I just laughed. I'd have bet the house it was going back together! Good one Mustie.
Mustie's mechanical autopsies.....love it.
Just realized I like true crime and engine tear downs. Should’ve been a coroner instead of a welder…
😀@@robertmckay694
Now with 20% more innuendos, and 5% more spider evictions
Love them.Great learning experience
Trained at MIT.Funky is a technical industry term.
James Condon had an engine in a video a while back that sounded a lot like this one. It turned out to have been assembled incorrectly with the balance shaft being off by one tooth. This caused it to just barely contact the crankshaft weight each revolution. No real damage had been done and lining up the marks fixed the issue. I couldn't tell from this video if the balance shaft was correctly installed.
I saw that video too it was off one tooth 😂
I was going to comment on that one as well, but you beat me to it!
Yes, I saw that James Condon video what you wrote is exactly what I was going to comment, it's amazing what you learn from RUclipsrs 😂
Was gonna right the exact same thing…
When he took the crankshaft out I thought there were areas on the outside of the counterbalances that seemed too shiny.
But didn't see any shiny areas on the balance shaft...
I went back and the camera angle here doesn't show the alignment marks before he pulled the balance shaft out.
I think that the issue was all caused by the bore. Once you honed the cylinder bore, it stopped the slapping of the piston in the bore. A bonus of the hone was that it also provided a smoother surface for the oil seal ring to get better unobstructed purchase on the surface -- hence, not more smoke from the blow-by. Great autopsy of the problem, and a great revival Dr. Frankenstein!!!
I think youre right.
@@oodiddy9778 that was my thought
Was the cylinder in backwards? I saw a small nick on the opposite side of spark plug...
I concur.!
I bet the piston skirt was well worn due to excessive drag from the bore corrosion. Might be worth squeezing the piston (gently)sideways in a vice to reduce bore clearance. We used to do this to Bultaco racing pistons. They were very expensive to replace, more than an average weeks wages and were prone to cracking due to slap from running in a loose bore. They rarely lasted 50 hours running time.
mustie lives in all of us........ as a little guy, i used to take all my toys apart, and the curiosity of how things work is still alive
The thing that jumped out at me was at 27:27 during tear down. The counter balance and piston balance were in line / sitting together with each other which I thought would cause excessive imbalance. When you put it together you lined up the marks and the balancer was now opposite the piston balancer lobe. Just a thought
I think you may be on to something. I watched and re-watched the counter balance removal. I wish he had checked the alignment marks before he removed it. There is another comment further down regarding the counter balance shaft.
"Enhance. Rotate 45, pan left 6. Enhance. Ok give me a hard copy right there"
Checked and double checked - I think you have spotted the possum in the garbage can there sir - well done!
@@johnpanek5203 Your recollections are not real - your memories come from one of Tyrell's nieces.
Clean the rust and the scratches out of the bore , replace the rings and put it back together , let it run
Morning everyone watching from Lincolnshire UK 🇬🇧
Watching from the Netherlands over here! XD Good afternoon!
Rural NY USA 💪🇺🇸
Bristol uk
Cherio!
good morning from Puyallup WA
Cars and Cameras on RUclips had a similar issue. They had a predator 420 with the decompression weight on the cam getting stuck. So, it wouldn't disengage properly when the engine started. I believe this engine was having a similar issue. Causing there to be knocking. There could have been some metal from the damage to the bore that got into it. When you took it apart it got dislodged while you messed with the decompression weight. Now that you messed with it and put it back together it appears to be operational. No guarantees on the longevity of it. The bore damage I believe is a separate situation that you properly diagnosed as moisture damage from sitting. Plus just wanted to add that your small engine disassembly videos were my inspiration to get me interested in working on small engines. I love fixing them and figuring out what makes them tick.
I see signs of a little piston slap, with the marks on the piston skirt and on the lower end of the bore, but that's somewhat normal, and generally wouldn't make a knocking sound. It's usually more of a "slapping/tapping" sound. But... if there was any play or slop on the bottom end, the slap from the change in position of the rod bottoming out, could have been pushing down/up on the crank. Everything seemed smooth during disassembly. Crazy that the knock went away after reassembly! Like you said, you may have tightened/adjusted something that got rid of the slop when reassembling. Oh, and your demonstration on how a governor works, was absolutely great! That alone would make a neat video or "short" video.
Classic take it apart and put it back together to fix it moment.
Weird knocking noise could be a valve sticking in a valve guide. I have experienced that once and it did sound like something was loose inside a cylinder.
The governor operation becomes a balance between the spring pressure of the throttle lever, which is adjustable, and the pressure applied by the flyweights in the governor gear. The more spring pressure the more force required by the flyweights which is accomplished by increased the engine speed. The balance point changes with spring pressure.
I bet that that knock would soon return with some more run time. The cylinder walls and piston are hurt pretty bad.
it was from the part of the cylinder that was really rough They dont have oil pressure so when it warmed up the tolerances got close in those areas causing some resistance. Not enough to seize it but enough to cause it to knock. Lawn mowers are not like car engines. if it had oil pressure it probably would not have made it knock. Honing the cylinder was what took off the nastiness enough to get the knock to go away.
Happy Sunday Morning everyone 💪
I had a guy bring me one very similar to that a few years ago, the cylinder looked much like yours. When it got here it wouldn't run at all. I cleaned the carb and it started but it was noisy.
The oil was fresh but the cart was a muddy mess. When I tore it apart I found the cylinder looked like it was de-laminating somehow. After tear down, I found that in the area where the cylinder was rough, the ring gap was zero. All the overlap and chatter marks in the bore was sticking the piston at the top of its travel making a loud tap or knock.
What I later found out was that his kids had taken it and swamped it sucking in water into a red hot motor. I honed it enough to take down any high spots, and put it back together. I never saw it again, the guy said it was still running a few years later.
Something that caught my eye on yours is that the rod looks heavier than the one I had here.
Keep in mind there's a ton of aftermarket parts out there for the Honda clone motors, including higher ratio rockers, aftermarket heads, rods, and cranks. Parts are cheap so its not uncommon to run across them where you wouldn't expect to find them. A non-stock rocker arm could cause interference with the push rod guide plate, but it rarely makes any noise. If it does its usually more a squeak then a knock and it usually self clearances itself rather quickly.
I always look forward to a Mustie1 Sunday video, great engine autopsy. Strange how it was making a lound clanking sound, and nothing was found. Great video, Mustie1 👍👍👍
Thank you Darren. Great tear down and reassembly. Always fun. ❤
Great detective work. The only thing I saw was when you took the piston out the gap on the top ring looked too big even allowing for it to get compressed when reinstalled? Maybe check the ring gaps. Could a small piece have been snapped off the end of the top ring running over the corrosion and this got munched, first by the piston cap then ground down the side of the piston hence the scores?
it was that rough area in the cylinder. Once it ran long enough it caused some resistance. Not enough to seize but enough to make it knock. Those engines dont have oil pressure so something like that would cause a noise. it it had oil pressure it might not have even made a knock. Honing the cylinder was the cure.
Love a good engine autopsy! I ran across the same issue once with a simple Briggs Quantum engine on a Toro mower. It was knockin’ like hell and I thought the rod was going to let go and shoot through the block. I put a replacement engine on it and sent it to a new home then I did an autopsy on the old Briggs Quantum. Not a damn thing wrong with it; no piston slap, no play in the rod bearing, no score marks on the cylinder walls or crank pin, no upper or lower crank bearing play, nothing! To this day I have no idea what the knocking was all about 🤷♂️
It’s crankshaft thrust play! There’s multiple different thickness gaskets available to get them quieter! although a small amount of play won’t hurt anything as it’s a trait of these engines but it’s easy to fix!
Yes as you get older losing a little spring tension can happen.😂
The valves start to leak and so on. Lose a little horsepower. It'll Be Fine.
😄
@@jlucasoundlove the cars and cameras reference numbers
😂😂😂😂😂 you got that right 😊
@@jamms992 I'm so glad the smart guy got his own show, to get away from the short fella who sticks the camera up his nose all the time (extreme selfie time), but I don't watch either of them anymore; maybe once in a great while.
Morning Mustie, the piston has an offset. I bet the piston was put in wrong, the arrow pointing the wrong way. That would explain the scoring on the skirt and lands plus the knock. I did that once when learning engines. Knocked the same way.
@ 39:43 you can see that the piston came out the right way up.
The arrow was pointing down, I believe it should be pointing up.@@unclegreybeard3969
Preface: I am not a small engine mechanic. That being said, I offer this for any future trouble shooting you or your viewers should do. My neighbor has a riding mower with a Kawasaki FR691V engine. Last year, it started smoking a bit when first started. I noticed but did not mention. This spring it got worse to the point that it smoked constantly. He mentioned it to me and told me he had located an engine rebuild kit. I asked him to hold off for a bit and let's look further. I suggested to him that maybe the valve seals had failed and explained to him what they were and how they worked. He ordered a set for $20+ figuring it was worth the gamble. If not, we'll rebuild it. We removed the spark plugs, inserted a soft rope in the cylinder to hold the valves closed, ran the piston to the top with the valve closed, removed the springs, replaced the seals and it has never smoked again. $20 about 4 hours time each and it's fixed.
Nice video Mustie! It’s been a while since a good autopsy video. Even if we didn’t find a tell, the process is always interesting.
I love watching you work and tinker with all kinds of stuff because I wanna go do stuff like that in the future, but one of my favourite random little touches to this channel is sometimes seeing that sharpied "4:30 Avocado Time" in the background. Cheers me up every time seeing that show up with zero context, haha
I’m just glad the project seems back on track.
These engine diagnostics are my absolute favorite!!
With the bottom end looking good, it might be worth checking the hord for a slightly oversized piston honing the bore to size and have an engine to use in another project.
Thanks Darren! I keep seeing the poor econoline truck patiently waiting in the background 🫤hoping to see more on it soon? 👍Thanks again 😎
@Mustie1, I think there was a chunk of carbon that got blasted off the face of the piston and it got wedged between the piston and the bore, and that is what scored the bore.
That is extremely likely.
Kevin B. was my neighbor until a few years ago. Brilliant man. Loves to tinker.
That engine looks to me like a great candidate for a top end rebuild, piston rings and gasket set - lap the valves and put the right plug in (?) and see if you get away with a dingle ball hone and a cheap nice engine! That would be a pretty sweet score in my opinion!
edit: ok well .. now I'm perplexed, there was about 10 minutes or so left in the video when I commented here.. I . I'm stunned.. that thing sounded just fine at the end. WTH man.. I don't know I mean the noise it was making before wasn't that horrible, not like a slap or anything.. It may well just have been that little plate where the lifter was.. I don't know though that knock sound, you'd expect a clank maybe a brighter click if it was just that plate tapping the lifter.. man.. might be worth doing a good bore and a top end and giver her hell!
Don't forget to oil the clutch bushing with motor oil. Keeping it oiled is not a problem if you're actually riding the kart with full clutch engagement (like 90% riding, 10% idling +/-) and all the parts there are rotating as one, but the issue becomes an issue if you use your kart and do a lot of idling and less running. Couple of drops on the crankshaft end (let the oil seep in) for every 2 hours of use.
I love how creative you are and use anything at your disposal to make what you envision. Thank you for all the hard work you put in and always staying true to who you are and the audience that follows you for you.
@Musti1 the curiosity that “gets you” is the curiosity that keeps us watching. Thanks for this!
Always a pleasure to watch you work, Mustie. I hope that you and yours have a great Christmas.
I wonder if the mark on the top of the piston is from where somebody poked a screwdriver or something through the plug hole to find TDC?
Happy & Merry, Mustie...and thank you for making my Sunday mornings more exciting! All my best to you and yours.
Awesome as always.Thanks for sharing and taking us along
When I was a teen in MN I would just take apart rough running engines and put them back together. 90% of the time it would cure the problem. I wouldn’t know what was fixed but I didn’t care. Here, a few tweaks were done like cylinder hone and correct counter weight reassembly, including a couple oil changes. Great video! I’m lovin the small engine tear downs. I learn so much.
Yeah, when I was in college, we used to call it the "dorm fix": Take it all apart and put it back together, and it usually, magically works better!
Now we’re talking, Honda power 💪 Gooday from AUS
Honda like power😆
@@mph5896Beijing clone power :D
Very interesting video Mustie that engine sounds sweet now put it in the stash 👌
Love it when you do this kind of deep dive into a blown engine
Appreciate the troubleshooting, Darren! I'm sure you will dig in and find the culprit! Have a Merry Christmas!
once again another great video, I couldn't spot anything that would've caused the problem but whatever it was you appeared to have inadvertently fixed it, love teardown and the explaining of the parts especially the governor.
You can’t pull out too soon, only too late😂😂😂
Thanks for taking the time for the autopsy! It was cool finding out the problem! 😊
My guess is this:
Someone put the wrong spark plug in, and it broke the tip of it off, making that dent. Then another - suitable - plug was put in. But the damage was already done. And that piece remained in the Bore and got chewed away making these scratches and also on the crankshaft ,- and ended in the oil as metal sludge . And because the engine knocked now, it was thrown away....
Love these autopsies of Motors and Carburetors! I wish I had that as a Young Girl. Would have love to watch it on TV. It's basically free education, what you can have these days on RUclips.
The big blow back through the carb makes me suspect something was off with the valvetrain
The knock sounded more like heavy metal than the push rod. You have the "touch"! Just your fondling the parts soothed them into compliance! Thanks for sharing, but your content is getting too risque for Sunday morning!
I got a free riding mower that supposedly had a rod knock.
Sounded really bad and the sign on it said 'Rod knock, if you can fix it it is yours'.
Turned out that ALL the mounting bolts were loose and it really sounded like a rod knock.
Tightened the mounting bolts and the mower sounded, functioned, and ran perfectly.
Strange as your motor sounded just like this one.
Thanks for sharing.
Thanks for another cool video on a Sunday morning! Watching from Salem NH!
Great video. the knocking was probably the misalignment on the balance shaft to the crank shaft ..seen it many times when people take apart these engines. they time the cam but not the balance shaft. keep up the great content
I'm of the opinion that a stray piece of flashing from the custom intake may have strayed into the cylinder somehow. Also, I looked back at your last video when you fired it up for the second time it coughed (around 28:41) and started smoking a little. I think that was when the material entered the cylinder. Then you reved it a smoke was blowing everywhere and you could actually hear the carnage.
Hey Mustie1, I know for a fact you would love working on vintage pocket watches from the late 19th century. Once you learn the rebuild on the basics, it's a magical experience when they beat back to life after decades! All your watch tools you can keep in one shoe box hehe. Take care out there!
My favourite day of the week. It's like Saturday mornings used to be when i was 9 😂. Greetings from Somerset UK 🇬🇧
It does have the same feel doesn't it? Great analogy
Could the noise be from the piston
ings slapping the corrosion on the bore? Maybe the honing that you did smoothed it out enough to remedy the slapping??
I think that it's a combination of things that plat was miss aligned and the decompression valve was out of sorts all in all a very interesting and enjoyable video thank you for sharing this with us six stars brother
Great video Darren ! Watched you tinker through most of your videos and I must say that you have fine diagnostic skills. Keep up the good work. Greetings from Ottawa CANADA.
Love a good teardown and rebuild in one episode!
Few things more fun than tearing down a misbehaving engine to figue out what went wrong, especially if you have a young person handy who wants to see what's going on. Greetings from North Carolina farm country.
I always love to watch these, watching over it it’s kinda weird how that happened. Noise could have been many different things. maybe around the pushrod wasn’t perfectly aligned or that plate kept smacking it but overall I think it’s quieter now unless the governor was interfering with something for some reason
Thank you for a great year. Merry Christmas and Happy New Year to you and yours.
Hey Mustie1... you did a great job explaining the governor, but I have to add to it because does more than you said. As soon as the engine is spinning at all, those weights start to lift off and at every RPM range they sit at a point of equilibrium toward the center of their range of motion. Which means that in addition to pulling the throttle down when it is spinning too fast, if you apply a load to the engine that causes it to bog down at all then they push down on that washer and OPEN the throttle.
That's why when you hit heavy grass with a lawn mower it bogs down and then throttles itself back up, then throttles down again, all without human intervention on the throttle lever. That style governor is also why when you shove the throttle to the max it overshoots then wavers a little bit and settles into the WOT RPM range... those weights have inertia that causes them to fly out, settle back in, out less, back in a little and then finally settle. :)
So
"spacer for exhaust flange"
I think you ought to weld on a thicker flange. That flange (that is installed) is so thin! I don't think it will stay flat (& sealed) for long!
Love the channel, I have some health issues that keep me inside the board. Your videos have helped me pass the time. They are great. You are a genius mechanic keep it up
well wishes to you james
Best channel on the web ! Merry Christmas from Minnesota
A pal was driving 400 miles so thought he'd change the oil quick on the street was a dry dusty summer and everything was covered in a good layer due to some construction near by,
Oil and filter all went well but he moved his van, clipped the edge of the pan.
It hit five cars and vans some were on the construction site ,two hours cleaning motors and the road.
I tried to look at the various shots in the videos from when you took it apart and when you reassembled it and set the timing on the counter balance. It's hard with the perspectives to be really precise but I think the video shows enough to say that the counter balance shaft was really off.
26:45 You can see how the alignment is. Looking at the groove in the crank shaft I would say it's pointing at about 1 O'clock. If you look at the bottom edge of the counter balance weight it's after 7 o'clock. Those two elements are almost 180 degrees away from each other.
1:08:20 You have reinstalled everything with the alignment correct. The crank shaft is almost 180 degrees out of phase from where it was when you disassembled it. I would expect the counter balance to be almost 180 degrees out of phase with its original position as well if it was originally aligned, but its about 90 degrees out of phase with its original position.
I'd say that the machine had some serious vibration going on.
Agree, engine was assembled wrong at the start. Video documents this. Engine definitely had some water in the cylinder, but wall damage is too severe to be just from corrosion. Someone here mentioned lack of ring clearance, and that's a good guess. Honing buys back a bit of ring clearance, so maybe that barely fixed it. Another observation is this is a very low hour engine. Hardly any carbon on piston... Sounds like multiple quality control issues at manufacture.
That’s my next 1hr20 sorted, thanks and merry Christmas Mustie..
Hello brother, i thing the push rod made that noise. I had done the same thing. I looked and looked. Then found a week spring that made the guide have slop . Its one of those things. Whenever you have multiple free areas your going to have a domino effect .especially when using knock off engines 😊 thanks for the show brother 🙏
Defiantly made for great viewing bro. Safe travels. Ken. 🎄
Good *morning* class! It's gonna be a great day. A cuppa coffee and a Mustie1 video to kick it off 😄
There’s a possibility that the cylinder got water in it and was hydro locked with water and someone tried to start it. The metallic parts could have gotten past the rings and into the bottom end. I don’t have any idea what caused the knocking unless it was that pushrod hitting on that retainer plate. Guess you’ve got another good engine now. A lot of the rattle was coming from the clamp tightening handles when you ran the engine after you got it back together. Can’t imaging what caused the smoke. 😮
The “Don’t grab that” had me roaring.
Thanks for the mystery engine treat,
A great and interesting video as always. A new lesson learned. From a production sense, when doing video audio is always pretty easy to get. You might think that we can't hear when you are away from the mic but we can. Maybe not great but we do hear you. From the video sense, Your camera does a great job of picking up your shots. What I've noticed is, that the camera doesn't need as much light as you might think it needs. When you were working on the block part of the dissection, you put the light up to the highest brightness. It tends to wash out the camera as the block is light in color and it reflects and washes out the picture. When you pull the light back to the medium brightness it shows a much better picture. I understand video production is always a work in progress and takes up as much of the video as the real video content itself. Keep up the great work. 99% of the production is always good. Have a great holiday and like I always say, EAT TOO MUCH!!😃😃
Looks like it’s built pretty good
Yes, I like the big main bearings and camshaft bearings. Big end shells would be nice though.
I've had 2 vw motors that have had an odd knock in them. One was a car i bought that had a knock and i found when i got home and ran it , it was a roll of insulation tape bouncing around in the fan. the other was the accelerator pump nozzle had left its seat in the carb and got drawn into a cylinder and beat itself to death between the piston and the head. Another motor i had a t work had lost the side electrode off a plug and had got embedded in the piston and done the same. The bore in your motor looks like its had water sitting in it. I also had a 600 series v8 Mercedes from the early 70s that wouldn't do a full revolution and had been sitting for 10 years . The carbon had slid off the piston and head to the outside of the cylinder and got between the piston and head . it was just enough to stop it. I had to pull the heads off to get the carbon out. Put it back together and it ran perfectly.
Mystery for sure, great video showing the investigation. Believe it or not but a mechanics stethoscope works to help pin point knocking sounds in the engine. I've used it many times and found it to be a great tool, even used it to find a fuel injector malfunction. Rookies can use it to identify, bad water pumps, alternators and mysterious engine noises. Great video as always.
The reason you didn't find anything was the scratches were caused by aluminum oxside melting at 3,762*F into a paste adhearing to the cylenders and ring. Not ending up in the oil.👉👉 Plus a good indication of a blow by on any engine gas or diesal. Is to look at the top of the piston where you'll see around the edges a half moon shape were the carbon has been cleaned off to bear aluminum. 🤔🤔I'm thinking the knocking was caused by the rings sticking making the piston tilt and skirt knocking the cylinder. 👍👍You did the right thing by honing the cylinder, but I'd also replace all the rings. Cha Ching !!!!!!!
Do you have any idea at what temperature aluminium oxide melts?
@@cambridgemart2075 Yes good question. I should of been more clearer. AO melts at 3,762*F which is higher then pure aluminum. But once it melts do to friction which is 3,000*F it paste up perminently bonding to the cylender's and rings.
@@kaydog2008 Do you mean Al2O3? There is no way you would reach 3000F in an small petrol (gas) engine, apart from which aluminium oxide forms a layer measured in nanometres thickness, so you would have microscopic amounts even if it did somehow melt.
Mark on piston is from the spark jumping and earthing out to piston instead of the plug electrode. Either broken or damaged plug at some point or bad block earth
I seriously suspect that push rod hitting that tab was the noise issue.
Honing the bore took care of the smoking.
2 years small engines vocational school my junior and senior years of high school helped diagnose that.
I wonder if parts are available for that engine.
If they are I'd see if theres a 10 over piston and rings available and hone the cylinder out to match.
It seems to be a fairly nice engine and I'm a nut about restoring pretty much anything I can.
Lot cheaper than buying a replacement engine if parts are available.
Hone it, ring it, slap it back together and run it!😆 Look forward to your vids every week!
I'm guessing the corrosion pitted the cylinder bad enough to cause the piston to rock and slap as it goes up and down
that does not explain why its not knocking after reassembly.
I think he is saying it was going up and the rings/piston were grabbing onto one side of the cylinder wall causing the piston to tilt in the bore which made the skirt slap the side of the cylinder over and over which made a knocking sound. Cleaning up the bore would then knock the high spots down, removing the resistance and allowing the piston to stay centered. That is what I kind of thought. @@osbberjen
I haven't heard anyone mention plastic gauge in many years, i haven't used it since since about 1979 in Automotive vo-tech in high school.
My modern Yamaha motorcycle service manual calls for them! They're still a thing.
I still use it all the time but the price now is crazy high, 55 years of using it to double check 😊😊
Hey Mustie...You forgot the little tiny one! Just started watching you again and enjoying it.
So much to catch up on.. ;)
That long intake you put on was over vaporizing the fuel air mixture causing pre-detonation.
Guaranteed....
'Over vapourising'??
no, vapo(no U)rizing, in other words too fine a fuel mist entering the combustion chamber causing pre-det, just look at the knock issue that went away by putting a std intake on.@@bananabrooks3836
I'm thinking that this engine received a new piston as it does not match the bore for wear. And I'd say that an incorrect plug was used on start up and possibly had the end of the electrode knocked off it and that what may have caused the scoring we saw and would account for the mark on the top of the piston. I'm also mystified that the knocking went away, but likely you fixed something that wasn't right when you re-assembled the engine. Oh, and kudos for removing the governor. Not really needed, anyway. Just leave a note on the engine to that effect when you stash it. As always, great work, an interesting video. Glad the dune buggy is now moving forward.
Merry Christmas and a Happy New Year to you and yours from the, currently warmish, little town of Moss Vale, here in regional New South Wales, Australia
The piston shouldn't be wearing on the bore. The piston floats on the rings. Least that's how it's supposed to work. The skirts can slap the bore some. Especially being as the bore was so chowdered up. Which may have been causing the rings to hang up on the bore some.
When you reved it when it was in the car there seemed to have blowback through the carb as if one of the valves was not shutting. With the wear on the pushrod could it have been misaligned or not seated into the rocker?
Those champion motors are great for boats. You drain the oil, bolt a chain on it and then throw it overboard when fishing. That odd shape catches the bottom and keeps your boat stationary.
Love these longer form videos.
What if,there was the wrong spark plug before the right one was put in.That might have been why there was a mark on the piston.There could have been a broken piece of the wrong spark plug left in the motor causing the rattle. So when you drained out the old oil it feel out.
Would love to see a Mustie full rebuild on that engine with some more honing, new ring set, new head gasket, new correct plug, carb cleaned and adjusted, everything torqued to spec and the machine sounding sweet.. Your satisfaction and ours would be immense on a job well done. Even James Condon would be impressed.
Merry Christmas Mustie! Love your vids!
Another great video! I am guessing that it was put together from the factory just slightly off and by taking it apart and putting it back right that eliminated the noise
The rust in cylinder probably indicates it had water in the combustion chamber, maybe from being out in weather with no air filter. if it had water inside and someone tried to start it could have bent the rod a bit and that could be causing the noise.
Other thing, at some time it may have had wrong and longer spark plug that hit the piston.
Otherwise, its a pretty good looking internals.
Great tutorial video.
I guess this was stored for an extended period with the piston at the bottom of the bore leading to the rust in the cylinder. I do wonder then if it was stuck and the previous owner did a very light hone and slapped a new piston in it because that piston doesn't look half as trashed as i'd expect it to be looking at that bore. The knocking is certainly odd. It didn't sound like slap and would still be heard now. I wonder if the big end, which looks marginal to me, now retorqued has caused it to quieten down temporarily? Pretty sure that mark on the piston crown is from the plug too, though maybe not THIS plug.
Enjoyed the video. Thanks for sharing
Enjoyed the video. Would like to have seen a 10-30 over bore with new pistons and rings. Always look forward to your videos. Thanks.
The wear on the push rod is kinda normal, you should see them when the cam compression release goes, there's a lot more wear on them and the tappets from all the debris in the engine - some people will just bump over the piston past tdc and keep running the engine, to their own demise.
Could have been the clutch and chain pulling the output shaft catiwampus.
Darren, I would put new rings in it, and get a new camshaft for it, and see if the problem is gone. If Honda has the same diameter rings, I would use them over the champion brand. A number of the oarts would interchange between both honda and the Champion engine, like carb, coil, recoil, etc.
Thank you for sharing.👍