For someone who rebuilds old chainsaws as a hobby, i would like to say thanks for putting the time in that video. Always thought it would work but never tried it. Great video! Thank you!
I like your approach to repairing an engine that is “hopeless”. That Husky would run for a long time without any replacement parts added. People who can’t afford to buy expensive oem parts take note: “You can do this with a little Common Sense and a bit of Elbow Grease applied. Good video Mike!
Very well done Dave. A little trick I use that I see you don't do is, If you're screwing in a bolt turn it counter clock wise first to find the thread start. You'll feel the bolt drop down every so slightly to sink up the threads.
I was thinking the same thing, a tip I learned by myself, turn it backwards until it drops in, especially when screwing into plastic. I really cringe when people use a power tool to install the cylinder hold down screws without checking to see the thread is engaged correctly, very easy to cross thread. Great video, I just purchased a Chinese after market gas-tank/handle for the 272XP and I see that the trigger assembly is not working like the stock one should with at least three defects that I can see on mine, ripped off again! Thanks, excellent video!!
Back in the 80's we had to fix stuff like that. There was no Internet. It was hard to get parts and even harder to get money. Of the ring gets to hot and loses it's spring, you can spread the gap with a nut, heat it then dunk it,retemper it. Sometimes you just gotta make due. Great video.
Thank you Dave for producing such a great video. The camera work was spot on the entire time. It is obvious that you know your way around a combustion engine ,but just as impressive to me was the ease with which you presented the fix.You imparted a good deal of method and technique during your teaching process. I especially liked the fact that you kept a clean work area. I also enjoyed that you were very eloquent, if I’ve watched 20 how to videos I’ve watched 100 + , for me it’s difficult to watch the fix when the presenter is stumbling over the choice of words and repeating themselves. Thank you, I look forward to seeing more of your videos.
Looking forward to watching you porting your saws!!! You take your time and explain each step in detail. You are training the next generation of chainsaw restorers and modifiers. I am one of them.
Wow, what a great comment. I appreciate that. I can say... I am not experienced in chainsaw porting. This isn't something I've gotten into. There is a fella Tinman's Saws that seems to be similar in age and has a great way of explanation. Check him out!
Not wishing to sell a bad saw being a personal choice as you put it is admorable sir and well done for being honest in your dealings a pity there are not many more with that attitude I have been had so to speak on a few occasions in my long life but as I say to my kids what goes round eventualy comes round and being honest always winns that I am sure Good vid and thanks for taking the time to share this with us mere mortals !!!!!!!!!!!
Yes, it's frustrating when you give people an opportunity to be honest but then lie to your face. Recently I had a guy sell me a Stihl chainsaw with damage undisclosed which I found when I got home. When confronted he just became aggressive and abusive. You can screw people over only so many times before it comes back to you in some way.
Good job I’ve cleaned up several cylinders in my life I cut the aluminum out of the bore with my pocket knife didn’t scratch the cylinder then used sand paper to clean up it sounds rough but I didn’t think I any thing to lose worked fine. I was very careful. Thanks for good informative videos
I know this is an old video, but to those who watched… when you see a piston that’s all cooked only around the exhaust side, that is usually from overheating. Factory mufflers on most saws are too restrictive and cause them to heat up when worked hard for a long time… if it was a poor gas/oil mixture the piston would be scored all the way around. I recommend, to whoever reads this, that you slightly modify your saws muffler to make it more free flowing. Not to make some hot rod saw, just so it doesn’t hold onto as much heat and risk smoking the piston like the one in the video
@@davidesparza8149 Best to pull the muffler off and have a look inside. I have a Stihl 462 and it is a very free flowing design, my Shindaiwa muffler has a restrictive cylinder inside it which will be removed to improve flow.
I have seen in automotive, when you have piston issue soak it with transmission fluid to build compression back up.I liked the advice about starting bolts by hand, after decades in automotive field have seen what being lazy can do. I have watched the younger guy's trying to get things done so fast that they will install spark plugs with cordless impact. Before I quit my job in the service station business I have noticed that my clients in landscape fields all switched to the highest octane fuel, they found it to be better for the fuel mix and caused less issue with carburetor. The down fall is the ethanol in gasoline
I didn't think that piston could be saved and used again. Kudos to you sir! I "blew up" my early 80's Stihl 024AVS and was too intimidated to try and save the top end so I ordered a cheap ebay replacement. Your video gave me the confidence to put in some elbow grease and at least try to save an OEM piston and cylinder. And they didn't even look as bad as yours did so I'm hopeful
Great video... I have a 2 stroke lawn mower with minor damage to piston and cylinder that I'm going to try this on. This has given me hope to re use the factory piston :) Cheers
I have got many chainsaws going this same way for my self and other peoples saws . The agent have said they are not worth fixing or going to need new cylinder and piston add labour to that and it comes close to the price of a new saw . I understand they want to put a warranty on the fix but if its just a firewood saw used a few times a year then many of the saws I’ve fixed have gone for years . Often its been run lean on the air/fuel mixture or the oil ratio is not correct . Once the ring pinches usual inline with the exhaust port then the saw wont start . Two strokes need good compression both on the top side of the piston and crankcase as the fuel/air mixture first enters below the piston through the reed valve and is compressed on the down stroke then as the piston clears the exhaust port the mix enters the cylinder . Any damage to the piston or ring will effect this process and saw wont start . Also poor crankshaft seals will also affect starting . These aren’t the only reasons a saw wont go but if its got good spark and fresh clean fuel and fuel filter plus a clean air filter and still wont start the its most likely a pinched ring or piston damage
I love this video. Thanks for walking us through not only the dissassembling of this Husq but your thought processes at ever step. This was a fascinating video to follow along and learn about the components and the 3-D “diagram/schematic” of this and most chainsaws. I came across a Husq 440x that appears like it was rarely used, but feels like it has little compression. I bought a compression tester for under $20 from Amazon which arrived yesterday. I’m eager to take on this rescue. I’m quite familiar with my Stihls and have always babied them in maintenance and blade sharpening, but this Husqvarna is a bit unfamiliar in details. Not no mo’. Thank you.
Good work, Dave! ...Tip on refinishing; use stainless steel wool for the final polish. I've never rebuilt a chainsaw, but have been working with wood and metal in various projects for years, from building/repairing violins, to building a tiny camper. I recently refinished a cheap single action revolver using fine sandpaper, and steel wool in running water, and little soap. Comes out super clean and polished!
If your using new rings, your better off with a slightly "rough" finish vs polished. You want the rings to seat in. New piston and rings should run through a few heat cycles before running full throttle, then move on to a load. Muratic acid works really good on the gaskets and gasket sealer used during the original factory assembly. I always use Yamabond semi-drying gasket sealer during assembly. Keeps gasket in place and helps with air leaks. Use any sealants VERY sparingly. a little goes a long way.
Perfect fit for my Echo CS-370, and the chain cuts very well ruclips.net/user/postUgkxBd8qUztQUCL8Rm1-aIig5ViBT2E_kO_6 . I had been using a Stihl chain that I had sharpened several times (sometimes at a shop, sometimes with my own electric chain sharpener), and there's no comparison -- the new chain cuts much better and holds its edge longer. We'll see how the new chain holds up when it needs sharpening, but for now I'm happy.
Thank you Dave. "Although I am Not mechanical minded I enjoyed the watch.I have my chainsaw certificate and have used chainsaw for years but I have always have them fixed professionally when needed by the guys like you who know what thet are doing... Cher :-)
Bless you for sharing your wisdom with us!!! Just an amazing amount of detail. I am an visual learner, so thank you so much for zooming in and taking your time explaining each step!!!
Surprised you didn't use 2 cycle oil for lube inside the cylinder. WD40 is basically water displacement and a mild solvent. It's good idea to let a saw engine warm up before giving it the beans. Nice repair, I try that if needed. Good video.
Exactly what i was thinking, also its easier to put piston and ring inside cylinder if you lube it with oil, wd40 is not meant for this I was really surprised he didnt do such a common and well known thing which makes huge difference Also cylinder survived so well because its a good quality, bad quality cylinder will not survive like this and will need replacement
Great video! I have a Stihl, that I was told, needing replacement of a scorched cylinder and piston. Your video has given me the confidence to at least try to fix on my own. Thank you for the time and effort you put into this presentation. Know that your two hours of work is reaping an even greater dividend than one revitalized chainsaw.
Hey Dave ... I really enjoyed this build and appreciate your strong ability to teach. Also ... this saw absolutely rips ! I was super impressed at how strong she runs and how much Ash and maple she swallowed up so quickly . Thanks fer selling me this saw brother !!
1: great content. I was looking to keep things as minimal as possible for my repairs. 2: your voice... you have a million dollar voice! Time for a youtube channel of you reading the classics.
Im in the process of doing just about the exact same thing. 272xp scored. Cleaned up the aluminium transfer in the cylinder and it looks like new. Sanded the piston just for fun and started realising this OEM beat piston is probably still better than a cheap china one. So I ordered a new piston ring and oil seals (incase the saw needs them). So I spent about 10$ on parts. Its amazing what a little elbow grease will do with these old quality parts. You can really go to town sanding the cylinders too. Really quite hard to get through the plating.
Fairplay! I've never done any serious chainsaw repairs and thought this was really impressive. I thought with the piston looking like that youd need a new one for sure.
Thanks, Dave you’re a godsend. I’ve got a echo with the same problem. This has been a great help. Thanks to you I am inspired to try to do the same on my 550 echo explanation point.
..I appreciate what you are doing here, but I would clean up the cylinder as best I could, and throw in a fresh Meteor piston with Caber ring..they are not that expensive, and it would likely be more reliable and last longer...I would reserve trying to save the piston for saws where the piston is unobtanium..272 pistons are easy to find, and a decent/very good aftermarket one is $25-$40...when you sand on a piston, it removes material and also can easily get it out of round or too much undersize...
So I cooked an 070 knockoff recently because I can't tune worth a darn ;) This video gives me something to think about when I pull it apart and evaluate the situation, thank you.
Also wondered why you did not coat the ring and cylinder with some oil instead of WD. I guess it worked. Would it have been helpful to have used a small engine cylinder hone to briefly to cross hatch the cylinder walls?
I do this sort of repair all the time on equipment for my own use (not for other people). I do spend $12 for a new set of Caber rings. I have found that Stihl chrome cylinders in straight gassed saws are rarely damaged and will clean up fine. I restore pistons that would make the purists gag. I do make sure that (1) the piston grooves are clean and free of aluminum transfer and (2) the bottom of the piston skirts are within reasonable tolerance (skirt to cylinder clearance < .0035). The critical areas are the rings (for compression) and the lower skirt (to prevent piston slap). They run fine.
Nice long video! Although I cringed when you started with 300. Were it me, I'd start at 600-1000 even if it meant a little more sanding. Agree with the pre-cleaning, or a bucket of steaming hot water with some Dawn. Once you've gone that far, I'd throw some engine paint on the exposed metal maybe. I've got a Poulan Pro that runs great but clutch won't spin and you've convinced me to give it a go.
Thanks Dave. I just got an Echo saw that won't start and found scour marks on the piston. I'm hoping to be able to save the cylinder and maybe even the piston after watching your video. Loved the muriatic acid trick. Something to think about. I heard to check for is gray discoloration on the crankshaft and down below in the case. I was told that should all be cleaned up with carburetor or brake cleaner or that material will work its way back up into the cylinder and cause more wear. I really enjoyed this video and the great detail.
Dave, I am so proud of you! I wasn't sure if the sanding was going to be good enough to work, but a combination of that and the Muratic acid, seems to have done the trick. Also a good diagnosis on the stuff you found wrong like the loose bolts and stuff. I am happy for you buddy.
I have had my 272xp for long time now and it still cuts like a new saw. With 28" bar, double dog, full skip chain and full wrap handle makes big jobs easy
Fun video! Great breakdown. I've got a couple old Poulan's with some scoring. One's got seized rings. I think (once my shop warms up this summer) I'll break them down and see what comes of a little clean up. Thanks again!
I have cleaned up quite a few seized up piston ring grooves, some of which were carboned up as well. I used a sharp piece of metal (old ring piece or chisel.) to cut away any excess metal. The ring should then have about 2 thou clearance, and should wobble about a bit when pushed into the groove from outside... making a figure of 8 with the piston. Hope that new piston and cylinder sits on your shelves for a few years
Hey Dave I got a little trick for you as you assemble the wristband and Ring and Kirsten take some of your oil mix for gas and an eyedropper and put a drop of oil on the wrist pin and on the rain and any part of the crank that you can reach it swollen sure at least the first firing that it is not dry
You definitely needed to remove any aluminium impregnated in the bore and on the surface of the piston ring. Aluminium to aluminium binds up strongly. Just try pushing an aluminium tube (say 1½") into another with 30-40 thou clearance, but with a slight burr on either. They will bind and you won’t get them apart. Not without sacrificing the outer tube or severely scoring both. If the tubes were steel, much less problem. I also learnt this the hard way when an ultralight powered by a 2 stroke 18Hp Fuji-Robin, seized at 500’. A repair after seizing before my ownership, had not cleaned the bore out adequately. No harm done (to me). Became a short flight in a poor performing glider. I’m not sure sanding the piston needed to totally remove any evidence of scoring, perhaps just the high points and any sharp ridges. I noticed there was a bit of rounding of the ring groove due to hand sanding. Perhaps gentle stroking with a fine flat file circumference wise, would be better, then finish with the finer paper. Much less hand sanding. Finally, to gauge how effective your fix was, squirt some oil down the plug hole and repeat the compression test. Any difference in the result will indicate how deficient is the piston / ring / bore seal. If you also performed both tests before repair, even more quantifiable. Use a few ml of gear oil (SAE 80 or 90) and give it a couple minutes to spread around the top of the piston. In 4 strokes, It is a technique used to separate bottom cylinder problems from top end problems. I.e worn rings, broken rings, scored bore/piston VERSUS valves (no tappet clearance, pitted or worn seats, bent stem), blown head gaskets, cracked or warped heads, hole in piston, etc. I’ve had a Stihl 066 sitting on the bench for a couple years. Won’t start after doing some hard continuous work. You’ve inspired me … well, at least to think about it. 😊
I really like this video and help me a lot.You are very good at explaining things and I want you to know that I got mine hot and I cracked the head right on top underneath the spark plug. Is there any way I could use JB weld or something? What would you do?
Nice to see that you have your channel going. I knew your name from being seen with Donnyboy. I watched one of his videos today on a decompression valve. I'm working on a Husqvarna K770 concrete saw. The customer stated that he can see fuel spraying out of the valve. Have you worked on any husqvarna 440's
I would like to add something that is going to make your job easier and more important the correct way to clean up your cylinder and your ring grove on your piston. Tools are a very important part of doing a job correctly I would like to have you check out a piston groove cleaner and a cylinder hone. When using sandpaper you are concentrated on one spot causing a low spot I realize it’s not much but to a person not experienced it might be a problem. Using a cylinder hone moving it up and down while spraying a lube like WD will clean up the cylinder as well as giving you the cross hatch needed to make ready to put it back together. I’m not saying that you are not doing anything wrong I’m simply giving you additional information and tools to make your work easier. With Respect. RR
@@DavesSmallEngines 👍 it would be great to see some vids on older Stihl, Jonsered ,Husqvarna ,Dolmar,Echo,Tanaka saws strimmers blowers if u happen to find any blown up examples that need redirection. It's great to see these bargain finds
This may end up saving me having to buy a new saw! I have an old Stihl 031AV that the saw shop told me is "junk" because the compression is bad. I was thinking there has to be a way to fix it. Thanks for showing me how! I hope to get it running soon. :)
I don't understand why people do this ! You should blow as much dirt off as possible BEFORE any disassembly. Then after you get the bar, handle and any covers off blow it off again ! Leaving dirt on the outside is just an invitation for it to get INSIDE the engine. Also I would use wet/dry sandpaper or emery cloth with water or oil.
I totally agree. I was a Tech/ Service Manager for a Honda motorcycle shop. Guys would bring dirt bikes in, that were due for a first service, which includes a valve clearance check. They’d be covered in dirt, or if it was “washed”, it was hit with a pressure washer, and not done correctly. I’d say, “ would you go roll around in a mud puddle,then show up at the hospital for a scheduled heart surgery?” It drove me nuts. We would tell them, it’s a $15. charge to wash it prior to service. The old man took $5. and whomever washed it got the rest lol.
What does sanding the scratches out actually do for the performance? As in, reducing the total diameter of the piston and increasing the gap between piston & cylinder wall. Piston ring polishing I understand that it's a better compression. Thanks, good info
I went to tech school for auto machine. We were taught to knurled piston skirts and tune them with a large fine cut mill file. Polishing the piston with fi e grits probably doesn't help, removing any bumps so piston won't continue scoring is. I was curious if the piston rings would have blow by, nice to see they didn't. I would be curious to see a more generally scored piston and cylinder go thru this and see if it worked ... did engine make enough compression to run and cut ok.
I usually rinse out the crankcase a couple of times with good two cycle and blow it out, good, with compressed air. This will get rid of most little fines. I then put assembly lube on the bearings before reassembly. I also put TB 1184 on both sides of the gasket on the cases and cylinder. I tighten all cylinder screws with a T wrench to a strong hand tight.
Thanx Dave! Greàt video,but please clean before teardown and use rags on top of crankcase before setting circlips on w/pin. I learned the hard way on a Harley Sportster.
That damage on the piston and cylinder may be caused by the unit running at high rpm with almost no load such as hedge cutting or very light delimbing. One time had a Stihl with similar damage and no pressure/vacuum leak. Stihl also does not cover this issue under warranty. Have to run the unit at lower throttle in light loads, or lower the high speed rpm. With some muriatic acid to disolve the aluminum and cylinder honing for cleanup you should have a good saw. Great to see how everyone rebuilds. Good experience. Best of luck for your saw!
I've got a Shindaiwa saw that I've noticed has some carbon build up on the piston at the exhaust exit. Is it worth pulling the thing apart to clean it up or just spray one of those foaming engine cleaner products (like Seafoam) in to the combustion chamber?
Just a quick question, what can be used as lube on piston rings, bearings and what not, I have no Idea about 2 strokes but for 4s I just use assembly lube
Why is there an arrow on the top of the piston to direct that side to the exhaust port? IOW is the piston different on one side than the other and how? I was wondering if the piston could be turned 180 when being put back in. Perhaps a diffirence is the location of the piston ring pin, which I am guessing is seen at 15:30-15:31 next to your thumb. At 27:00 you seem to be aware of it when installing the ring but don't mention it.
hopefully it's not a lemon!
Donyboy!!! Thanks for stopping in. Hoping to get your honest critique on my video. It was a lemon.... but I made lemonade!!!!
@@DavesSmallEngines i knew you could!
@@DavesSmallEngines compresion ? 140 psi good ?
@@Sensei948 yep!
@@DavesSmallEngines ruclips.net/video/jvBvHr9Pcmo/видео.html naprawi to jeszcze ?
Glad I'm not the only one who works on a saw at night and then can't eagerly check it out because it will wake the neighbors :)
If the neighbors are sawing logs in bed, why can't I in my driveway?
For someone who rebuilds old chainsaws as a hobby, i would like to say thanks for putting the time in that video. Always thought it would work but never tried it. Great video! Thank you!
You’re very welcome, William!
I like your approach to repairing an engine that is “hopeless”. That Husky would run for a long time without any replacement parts added. People who can’t afford to buy expensive oem parts take note: “You can do this with a little Common Sense and a bit of Elbow Grease applied.
Good video Mike!
In an age of need2repair. ...good advice .
Very well done Dave. A little trick I use that I see you don't do is, If you're screwing in a bolt turn it counter clock wise first to find the thread start. You'll feel the bolt drop down every so slightly to sink up the threads.
Yes sir! If I find turning it in by hand is a bit “off”... I’ll turn it back and try and reset. Good point!
I learned that trick back in the 70's, but never told anyone because everyone thinks your nutz
Good tip, my dad taught me that when i was a kid, still use it. always.
Yes well done 👍
I was thinking the same thing, a tip I learned by myself, turn it backwards until it drops in, especially when screwing into plastic. I really cringe when people use a power tool to install the cylinder hold down screws without checking to see the thread is engaged correctly, very easy to cross thread. Great video, I just purchased a Chinese after market gas-tank/handle for the 272XP and I see that the trigger assembly is not working like the stock one should with at least three defects that I can see on mine, ripped off again! Thanks, excellent video!!
Back in the 80's we had to fix stuff like that. There was no Internet. It was hard to get parts and even harder to get money. Of the ring gets to hot and loses it's spring, you can spread the gap with a nut, heat it then dunk it,retemper it. Sometimes you just gotta make due. Great video.
thank you for this idea 🤔 i have an old 1961 mcculloch 1-71 am working on right now and i noticed the ring did kind of lose its spring. thanks
Thank you Dave for producing such a great video. The camera work was spot on the entire time.
It is obvious that you know your way around a combustion engine ,but just as impressive to me was the ease with which you presented the fix.You imparted a good deal of method and technique during your teaching process. I especially liked the fact that you kept a clean work area.
I also enjoyed that you were very eloquent, if I’ve watched 20 how to videos I’ve watched
100 + , for me it’s difficult to watch the fix when the presenter is stumbling over the choice of words and repeating themselves. Thank you, I look forward to seeing more of your videos.
Looking forward to watching you porting your saws!!!
You take your time and explain each step in detail. You are training the next generation of chainsaw restorers and modifiers.
I am one of them.
Wow, what a great comment. I appreciate that. I can say... I am not experienced in chainsaw porting. This isn't something I've gotten into. There is a fella Tinman's Saws that seems to be similar in age and has a great way of explanation. Check him out!
Not wishing to sell a bad saw being a personal choice as you put it is admorable sir and well done for being honest in your dealings a pity there are not many more with
that attitude I have been had so to speak on a few occasions in my long life but as I say to my kids what goes round eventualy comes round and being honest always winns
that I am sure Good vid and thanks for taking the time to share this with us mere mortals !!!!!!!!!!!
Yes, it's frustrating when you give people an opportunity to be honest but then lie to your face. Recently I had a guy sell me a Stihl chainsaw with damage undisclosed which I found when I got home. When confronted he just became aggressive and abusive. You can screw people over only so many times before it comes back to you in some way.
Huskys are the best . Great video
I've done this back in eighty nine good to see someone as savvy as me in a pinch keep going making content.😍
Good job I’ve cleaned up several cylinders in my life I cut the aluminum out of the bore with my pocket knife didn’t scratch the cylinder then used sand paper to clean up it sounds rough but I didn’t think I any thing to lose worked fine. I was very careful. Thanks for good informative videos
I know this is an old video, but to those who watched… when you see a piston that’s all cooked only around the exhaust side, that is usually from overheating. Factory mufflers on most saws are too restrictive and cause them to heat up when worked hard for a long time… if it was a poor gas/oil mixture the piston would be scored all the way around. I recommend, to whoever reads this, that you slightly modify your saws muffler to make it more free flowing. Not to make some hot rod saw, just so it doesn’t hold onto as much heat and risk smoking the piston like the one in the video
Please describe the modifications to a stock muffler that you recommend.
@@davidesparza8149
Best to pull the muffler off and have a look inside. I have a Stihl 462 and it is a very free flowing design, my Shindaiwa muffler has a restrictive cylinder inside it which will be removed to improve flow.
I have seen in automotive, when you have piston issue soak it with transmission fluid to build compression back up.I liked the advice about starting bolts by hand, after decades in automotive field have seen what being lazy can do. I have watched the younger guy's trying to get things done so fast that they will install spark plugs with cordless impact. Before I quit my job in the service station business I have noticed that my clients in landscape fields all switched to the highest octane fuel, they found it to be better for the fuel mix and caused less issue with carburetor. The down fall is the ethanol in gasoline
I didn't think that piston could be saved and used again. Kudos to you sir! I "blew up" my early 80's Stihl 024AVS and was too intimidated to try and save the top end so I ordered a cheap ebay replacement. Your video gave me the confidence to put in some elbow grease and at least try to save an OEM piston and cylinder. And they didn't even look as bad as yours did so I'm hopeful
Great video... I have a 2 stroke lawn mower with minor damage to piston and cylinder that I'm going to try this on. This has given me hope to re use the factory piston :)
Cheers
That was great. Thank you. I've got a 394XP and I'll be tearing it down instead of selling due to your video.
Glad I found you Dave. I've got 6 dead chainsaws and a grumpy Stil tiller. Hoping I can resurrect them all!
I have got many chainsaws going this same way for my self and other peoples saws . The agent have said they are not worth fixing or going to need new cylinder and piston add labour to that and it comes close to the price of a new saw . I understand they want to put a warranty on the fix but if its just a firewood saw used a few times a year then many of the saws I’ve fixed have gone for years . Often its been run lean on the air/fuel mixture or the oil ratio is not correct . Once the ring pinches usual inline with the exhaust port then the saw wont start . Two strokes need good compression both on the top side of the piston and crankcase as the fuel/air mixture first enters below the piston through the reed valve and is compressed on the down stroke then as the piston clears the exhaust port the mix enters the cylinder . Any damage to the piston or ring will effect this process and saw wont start . Also poor crankshaft seals will also affect starting . These aren’t the only reasons a saw wont go but if its got good spark and fresh clean fuel and fuel filter plus a clean air filter and still wont start the its most likely a pinched ring or piston damage
I love this video. Thanks for walking us through not only the dissassembling of this Husq but your thought processes at ever step. This was a fascinating video to follow along and learn about the components and the 3-D “diagram/schematic” of this and most chainsaws.
I came across a Husq 440x that appears like it was rarely used, but feels like it has little compression. I bought a compression tester for under $20 from Amazon which arrived yesterday. I’m eager to take on this rescue. I’m quite familiar with my Stihls and have always babied them in maintenance and blade sharpening, but this Husqvarna is a bit unfamiliar in details. Not no mo’. Thank you.
Good work, Dave! ...Tip on refinishing; use stainless steel wool for the final polish.
I've never rebuilt a chainsaw, but have been working with wood and metal in various projects for years, from building/repairing violins, to building a tiny camper. I recently refinished a cheap single action revolver using fine sandpaper, and steel wool in running water, and little soap. Comes out super clean and polished!
If your using new rings, your better off with a slightly "rough" finish vs polished. You want the rings to seat in. New piston and rings should run through a few heat cycles before running full throttle, then move on to a load. Muratic acid works really good on the gaskets and gasket sealer used during the original factory assembly. I always use Yamabond semi-drying gasket sealer during assembly. Keeps gasket in place and helps with air leaks. Use any sealants VERY sparingly. a little goes a long way.
Perfect fit for my Echo CS-370, and the chain cuts very well ruclips.net/user/postUgkxBd8qUztQUCL8Rm1-aIig5ViBT2E_kO_6 . I had been using a Stihl chain that I had sharpened several times (sometimes at a shop, sometimes with my own electric chain sharpener), and there's no comparison -- the new chain cuts much better and holds its edge longer. We'll see how the new chain holds up when it needs sharpening, but for now I'm happy.
Nice work on the ol Husky..👌 They are worth it!
Thank you Dave. "Although I am Not mechanical minded I enjoyed the watch.I have my chainsaw certificate and have used chainsaw for years but I have always have them fixed professionally when needed by the guys like you who know what thet are doing... Cher :-)
Bless you for sharing your wisdom with us!!!
Just an amazing amount of detail.
I am an visual learner, so thank you so much for zooming in and taking your time explaining each step!!!
Thanks so much for watching!
Surprised you didn't use 2 cycle oil for lube inside the cylinder. WD40 is basically water displacement and a mild solvent. It's good idea to let a saw engine warm up before giving it the beans. Nice repair, I try that if needed. Good video.
Ever heard of cold seizing…no way would I be revving a cold saw like that!
@@tjgrossman did it seize? No, good.
Exactly what i was thinking, also its easier to put piston and ring inside cylinder if you lube it with oil, wd40 is not meant for this
I was really surprised he didnt do such a common and well known thing which makes huge difference
Also cylinder survived so well because its a good quality, bad quality cylinder will not survive like this and will need replacement
Great video! I have a Stihl, that I was told, needing replacement of a scorched cylinder and piston. Your video has given me the confidence to at least try to fix on my own. Thank you for the time and effort you put into this presentation. Know that your two hours of work is reaping an even greater dividend than one revitalized chainsaw.
Hey William! That’s what it is all about for me!
* Tip from a mechanic.....If it has at least 50lbs compression, it will run.
Perfectly usable! The Meteor piston and separate rings will make that say an awesome machine. NIce jobl Dave!
You bet!
I always wondered if it was possible to repair those cylinders after the scoring and your video answered my question so thank you and great video !!!
Hey Dave ... I really enjoyed this build and appreciate your strong ability to teach.
Also ... this saw absolutely rips ! I was super impressed at how strong she runs and how much Ash and maple she swallowed up so quickly . Thanks fer selling me this saw brother !!
Awesome!!!
1: great content. I was looking to keep things as minimal as possible for my repairs. 2: your voice... you have a million dollar voice! Time for a youtube channel of you reading the classics.
Im in the process of doing just about the exact same thing. 272xp scored. Cleaned up the aluminium transfer in the cylinder and it looks like new. Sanded the piston just for fun and started realising this OEM beat piston is probably still better than a cheap china one. So I ordered a new piston ring and oil seals (incase the saw needs them). So I spent about 10$ on parts. Its amazing what a little elbow grease will do with these old quality parts. You can really go to town sanding the cylinders too. Really quite hard to get through the plating.
did I just learn how to repair cylinder head and piston. Thanks Dave nice video!
Fairplay! I've never done any serious chainsaw repairs and thought this was really impressive. I thought with the piston looking like that youd need a new one for sure.
Hey Legacy! Thanks!!! It turned out well. I can't guarantee how long it will last however.... it seems to be working great still!
Thanks, Dave you’re a godsend. I’ve got a echo with the same problem. This has been a great help. Thanks to you I am inspired to try to do the same on my 550 echo explanation point.
..I appreciate what you are doing here, but I would clean up the cylinder as best I could, and throw in a fresh Meteor piston with Caber ring..they are not that expensive, and it would likely be more reliable and last longer...I would reserve trying to save the piston for saws where the piston is unobtanium..272 pistons are easy to find, and a decent/very good aftermarket one is $25-$40...when you sand on a piston, it removes material and also can easily get it out of round or too much undersize...
nice work Dave
I have a Husqvarna 61 that I just love. Its never let me down.
Great saws!
Nice to know you can save a piston and ring thats quite damaged. Great job Thanks .
Thanks Mark!
Great job bringing it back from the dead 👍
So I cooked an 070 knockoff recently because I can't tune worth a darn ;) This video gives me something to think about when I pull it apart and evaluate the situation, thank you.
Pretty good skill set especially if you find especially if you find yourself in a deserted island with no parts.
Great video, that saw will cut much better with a sharp chain.
Thanks for the tip! You're right. Chain has been sharpened and its running great!
Also wondered why you did not coat the ring and cylinder with some oil instead of WD. I guess it worked. Would it have been helpful to have used a small engine cylinder hone to briefly to cross hatch the cylinder walls?
Awesome video!! Really enjoyed it. Thank you sir!!
I do this sort of repair all the time on equipment for my own use (not for other people). I do spend $12 for a new set of Caber rings. I have found that Stihl chrome cylinders in straight gassed saws are rarely damaged and will clean up fine. I restore pistons that would make the purists gag. I do make sure that (1) the piston grooves are clean and free of aluminum transfer and (2) the bottom of the piston skirts are within reasonable tolerance (skirt to cylinder clearance < .0035). The critical areas are the rings (for compression) and the lower skirt (to prevent piston slap). They run fine.
Beast of a saw I've bin run'n the 70cc saw forever, the 372xp/2172cs the best most productive saws ever built, logger life
That’s awesome Jason. I love it!
Good afternoon, very interesting. I am going to try one of my old saws.I have nothing to lose. Thank you for taking the time to video
Hey Steve! You’re right - nothing to lose. What saw are you going to try it out on?
Dave u have ended up with a nice saw that many would like to own . Great repair
You got that right!
Good work . Nice pertinent comments. Camera work was of good quality. You have a good voice for naratn. Keep up the good work.
Thanks Harold! Stay tuned for more!
I have done it before lots of TLC and piston rings and it'll work !
Sounds great!
Great instruction! You can work in my shop any time! Just put the lid back on the acid immediately......
Yes sir! Will do. Thanks Don!
I really enjoy to watch it!
Good job man keep it up
DWD great information for a ignorant newbie like me. Thank you!
Hey Collin! I’m still learning too! Cheers
Nice long video! Although I cringed when you started with 300. Were it me, I'd start at 600-1000 even if it meant a little more sanding. Agree with the pre-cleaning, or a bucket of steaming hot water with some Dawn. Once you've gone that far, I'd throw some engine paint on the exposed metal maybe. I've got a Poulan Pro that runs great but clutch won't spin and you've convinced me to give it a go.
Tried all that with an old Johnsered years ago but no luck. The compression did not pop up enough. Happy for you and nice work.
Thanks Richard! I think it’s always worth a shot.
Thanks Dave. I just got an Echo saw that won't start and found scour marks on the piston. I'm hoping to be able to save the cylinder and maybe even the piston after watching your video. Loved the muriatic acid trick. Something to think about. I heard to check for is gray discoloration on the crankshaft and down below in the case. I was told that should all be cleaned up with carburetor or brake cleaner or that material will work its way back up into the cylinder and cause more wear. I really enjoyed this video and the great detail.
This was fascinating. Like watching a hip replacement for a chainsaw. Thank for sharing this. I may have to do this for an old Jonsered I picked up.
Totally worth it to try - nothing to lose!
Excellent video....very well done all the way around. Good job.
Thanks for making this video very helpful and educational 👍🏽👍🏽
Dave, I am so proud of you! I wasn't sure if the sanding was going to be good enough to work, but a combination of that and the Muratic acid, seems to have done the trick. Also a good diagnosis on the stuff you found wrong like the loose bolts and stuff. I am happy for you buddy.
Thank you!! I appreciate it.
Awesome fix man im really impressed how well that worked
I have had my 272xp for long time now and it still cuts like a new saw. With 28" bar, double dog, full skip chain and full wrap handle makes big jobs easy
Fun video! Great breakdown. I've got a couple old Poulan's with some scoring. One's got seized rings. I think (once my shop warms up this summer) I'll break them down and see what comes of a little clean up. Thanks again!
You’re welcome! Thanks for stopping in.
Hose clamps make great ring compressors.
Good job. Getting her going.
I'll give one a try!
I have cleaned up quite a few seized up piston ring grooves, some of which were carboned up as well. I used a sharp piece of metal (old ring piece or chisel.) to cut away any excess metal. The ring should then have about 2 thou clearance, and should wobble about a bit when pushed into the groove from outside... making a figure of 8 with the piston. Hope that new piston and cylinder sits on your shelves for a few years
Very good video. I really enjoyed watching. Thanks for sharing.
Hey Dave I got a little trick for you as you assemble the wristband and Ring and Kirsten take some of your oil mix for gas and an eyedropper and put a drop of oil on the wrist pin and on the rain and any part of the crank that you can reach it swollen sure at least the first firing that it is not dry
Well done. Never occurred to me to try this.
Thanks!
Good Job Dave. I bet it will run for another 10 years just like it is.
You definitely needed to remove any aluminium impregnated in the bore and on the surface of the piston ring. Aluminium to aluminium binds up strongly. Just try pushing an aluminium tube (say 1½") into another with 30-40 thou clearance, but with a slight burr on either. They will bind and you won’t get them apart. Not without sacrificing the outer tube or severely scoring both. If the tubes were steel, much less problem.
I also learnt this the hard way when an ultralight powered by a 2 stroke 18Hp Fuji-Robin, seized at 500’. A repair after seizing before my ownership, had not cleaned the bore out adequately. No harm done (to me). Became a short flight in a poor performing glider.
I’m not sure sanding the piston needed to totally remove any evidence of scoring, perhaps just the high points and any sharp ridges. I noticed there was a bit of rounding of the ring groove due to hand sanding. Perhaps gentle stroking with a fine flat file circumference wise, would be better, then finish with the finer paper. Much less hand sanding.
Finally, to gauge how effective your fix was, squirt some oil down the plug hole and repeat the compression test. Any difference in the result will indicate how deficient is the piston / ring / bore seal. If you also performed both tests before repair, even more quantifiable. Use a few ml of gear oil (SAE 80 or 90) and give it a couple minutes to spread around the top of the piston. In 4 strokes, It is a technique used to separate bottom cylinder problems from top end problems. I.e worn rings, broken rings, scored bore/piston VERSUS valves (no tappet clearance, pitted or worn seats, bent stem), blown head gaskets, cracked or warped heads, hole in piston, etc.
I’ve had a Stihl 066 sitting on the bench for a couple years. Won’t start after doing some hard continuous work. You’ve inspired me … well, at least to think about it. 😊
Excellent Video..Thank you for sharing your knowledge!!
Love your show. Though it really messed with my head watching you work without the top on that bottle of acid.
I really like this video and help me a lot.You are very good at explaining things and I want you to know that I got mine hot and I cracked the head right on top underneath the spark plug. Is there any way I could use JB weld or something? What would you do?
Nice to see that you have your channel going. I knew your name from being seen with Donnyboy. I watched one of his videos today on a decompression valve. I'm working on a Husqvarna K770 concrete saw. The customer stated that he can see fuel spraying out of the valve. Have you worked on any husqvarna 440's
How did you know the engine was blown? What were the symptoms? Excellent video.
I would like to add something that is going to make your job easier and more important the correct way to clean up your cylinder and your ring grove on your piston. Tools are a very important part of doing a job correctly I would like to have you check out a piston groove cleaner and a cylinder hone. When using sandpaper you are concentrated on one spot causing a low spot I realize it’s not much but to a person not experienced it might be a problem. Using a cylinder hone moving it up and down while spraying a lube like WD will clean up the cylinder as well as giving you the cross hatch needed to make ready to put it back together. I’m not saying that you are not doing anything wrong I’m simply giving you additional information and tools to make your work easier. With Respect. RR
Dave you have been a good student, done your homework and are adopting the same style as the miestro your mentor don. Enjoyable vid
Thank you kindly!
@@DavesSmallEngines 👍 it would be great to see some vids on older Stihl, Jonsered ,Husqvarna ,Dolmar,Echo,Tanaka saws strimmers blowers if u happen to find any blown up examples that need redirection. It's great to see these bargain finds
@@tc3603 I have a Partner Pioneer 7000 I bought at a garage sale fully disassembled. Would you like to see a video on the rebuild?
@@DavesSmallEngines that would be great. Cannot beat the older stuff . Looking forward to it
@@tc3603 sounds good... I have a much bigger project I’m about to get underway. Well, several actually. But this one is pretty big!
Putting this one solidly in the “Win” column.
Just subscribed!
Thanks so much. I’ll keep making more videos! Appreciate the support!
Looks to be an OEM cylinder, good stuff.
Thanks for watching!!!
Any opinions on the value of replacing the piston rotated by 180 .
This may end up saving me having to buy a new saw! I have an old Stihl 031AV that the saw shop told me is "junk" because the compression is bad. I was thinking there has to be a way to fix it. Thanks for showing me how! I hope to get it running soon. :)
Hey Caleb! Sounds great. Let me know!!!
I don't understand why people do this ! You should blow as much dirt off as possible BEFORE any disassembly. Then after you get the bar, handle and any covers off blow it off again ! Leaving dirt on the outside is just an invitation for it to get INSIDE the engine.
Also I would use wet/dry sandpaper or emery cloth with water or oil.
I agree Jack - however with my air compressor I made certain that nothing was inside before reassembly.
I thought the same thing.
I totally agree. I was a Tech/ Service Manager for a Honda motorcycle shop. Guys would bring dirt bikes in, that were due for a first service, which includes a valve clearance check. They’d be covered in dirt, or if it was “washed”, it was hit with a pressure washer, and not done correctly.
I’d say, “ would you go roll around in a mud puddle,then show up at the hospital for a scheduled heart surgery?”
It drove me nuts. We would tell them, it’s a $15. charge to wash it prior to service. The old man took $5. and whomever washed it got the rest lol.
@@chipper442 I would happily pay the $15 !
What does sanding the scratches out actually do for the performance? As in, reducing the total diameter of the piston and increasing the gap between piston & cylinder wall.
Piston ring polishing I understand that it's a better compression. Thanks, good info
I went to tech school for auto machine. We were taught to knurled piston skirts and tune them with a large fine cut mill file. Polishing the piston with fi e grits probably doesn't help, removing any bumps so piston won't continue scoring is.
I was curious if the piston rings would have blow by, nice to see they didn't. I would be curious to see a more generally scored piston and cylinder go thru this and see if it worked ... did engine make enough compression to run and cut ok.
I usually rinse out the crankcase a couple of times with good two cycle and blow it out, good, with compressed air. This will get rid of most little fines. I then put assembly lube on the bearings before reassembly. I also put TB 1184 on both sides of the gasket on the cases and cylinder. I tighten all cylinder screws with a T wrench to a strong hand tight.
I’m going to start doing that! Thanks!
Thanx Dave! Greàt video,but please clean before teardown and use rags on top of crankcase before setting circlips on w/pin. I learned the hard way on a Harley Sportster.
Good tips Ross, thanks!
Have you replaced it yet or still running that piston?
That damage on the piston and cylinder may be caused by the unit running at high rpm with almost no load such as hedge cutting or very light delimbing.
One time had a Stihl with similar damage and no pressure/vacuum leak.
Stihl also does not cover this issue under warranty.
Have to run the unit at lower throttle in light loads, or lower the high speed rpm.
With some muriatic acid to disolve the aluminum and cylinder honing for cleanup you should have a good saw.
Great to see how everyone rebuilds. Good experience.
Best of luck for your saw!
Hey! Thanks for the great comments. Much appreciated. I had great luck with it - 160 PSI now! Cheers!
I use a large ice block tray to store small screws etc when disassembling small engines stops them getting lost.
Have you ever seen one where it was badly scored the intake and exhaust side of the piston and cylinder ? Just came across your channel
I've got a Shindaiwa saw that I've noticed has some carbon build up on the piston at the exhaust exit. Is it worth pulling the thing apart to clean it up or just spray one of those foaming engine cleaner products (like Seafoam) in to the combustion chamber?
Just a quick question, what can be used as lube on piston rings, bearings and what not, I have no Idea about 2 strokes but for 4s I just use assembly lube
A bit of overheating due to build up on cooling fins. Got to clean those fins.
Such an informative video. Thanks for sharing.
Thanks Mike! Appreciate the kind words.
Good video Dave thanks for your tips will come in usefull
Thanks for watching!
Why is there an arrow on the top of the piston to direct that side to the exhaust port? IOW is the piston different on one side than the other and how? I was wondering if the piston could be turned 180 when being put back in. Perhaps a diffirence is the location of the piston ring pin, which I am guessing is seen at 15:30-15:31 next to your thumb. At 27:00 you seem to be aware of it when installing the ring but don't mention it.
Good job you gotta do what you gotta do Go old school do what you gotta do I like that good job
Thanks Dave,
I learned something today!
Thanks Dan!
Nice! I didn't think this was possible
Great job!