That was exactly what happened to myb361. Your piston was also kissing the counterweights at BDC. To check this I coat the counterweights with Assembly Lube. Install the piston on the connecting rod. Put the cylinder on and rotate the crank around for several revolutions and then pull the piston off and check for assembly lube on the skirt of the piston. If there is any, I mark those areas and grind off the markings with my Dremel. I keep doing this test until there is no more assembly lube on the piston skirt. I think I did the 361 about five times. After it came out clean I ground the whole inside Skirt area one more time to build in some added clearance. I also sanded the bottom of the skirt until the height of the piston was the same on each side of the piston. I did one final check after I was through to make sure the piston was not contacting the counterweights on the crank.
your not the only one mate I'm a second generation arborist I have a ms 440 and exactly this happend on the intake side . . my con rod bent too thou . . so I did a near full rebuilding . . new bearings new conrod an new piston . . now she runs like new :-)
It wasn’t smacking the counterweights but I think it was just kissing it. Farmertec had relieved the skirt but not enough. Walt found the same problem on the 361 that he built. I bought a brand new cylinder, piston and crank from Farmertec and put them in. Mine hit so hard it threw a piston pin circlip and bent the rod. Aa at idle.
It is difficult to clean out the crankcase of a 440. I just did it because my 440 likes to eat circlips. If it had been running at the time I would have had to split the cases but it came out when I was cranking it and I only had to get it out and a few pieces of the piston. It is back together, now, and running fine. I did wash out the crankcase with two cycle, break cleaner and compressed air, several times and re- lubed everything good before re-assembly.
yeah my 440 to also quite hard to clean up. now my problem is the oil pump to the chain itself. the oil keep leaking under body and oil didnt come out to the chain bar. 😩
ayen ayie the 440 has a metal hose pumping the oil from the pump to the discharge hole in the case. Make sure that metal hose is properly connected into the case. I got two lil pumps in my 440 kit and the first one did not connect, properly. I replaced the first one with the second one and it worked fine. As I remember, the metal hose has a little o ring on it and it snapped into place when connected properly. If mine was leaking, I would just replace it with another one. The bend in the metal hose must be correct to get it to lock in.
ayen ayie I forgot to add the worm gear arm can hit the metal hose, so make sure it does not, because it can destroy your worm gear. Connect the metal hose and then bolt down the oil pump because it can disconnect if you do it otherwise. It is a very delicate installation, so be careful.
I also noticed in the video you said the saw idles alot on concrete. idle is when it's at the leanest should never let them idle for long periods of time. If you haven't done a leak down test I would run it for 5mins cutting and pull the plug and see what it looks like it should be light brown in color if it's white it's to lean and sacking air through crank seals more than likely with all that metal in the bottom end
The saw could idle for 2-3 minutes while I move Logs around. I did not want to bake the saw by just shutting it off right after a cut. Maybe on this saw I need to let it idle for 15-20 seconds than shut it off. I'm bad about pulling the plug and reading it. too lazy.
You were lucky, when my 361 ate a circlip it bent the rod and it had more damage than you seem to have experienced. It is doing fine, now but I had to completely rebuild it. I bought a new short block but these are not assembled according to my specs, so it would not pass a pressure test. Therefore I rebuilt my existing cases. Farmertec does not use any sealant on the case or base gasket. I use 1184 on the case gasket and Dirko HT on the base gasket. I did replace the crank seals in the 361 but not my 440. If it failed on the intake side you lost a circlip and from the damage, you lost it running.
This is not an issue of it dieing because it is a stihl, the damage to the piston and the disintegration is a sign of dirt injection wearing it thin to the point of failure. Clean your filters more often and keep the chain sharp and your problem will be solved
Do this go to a shop and Dirko sealant but it on both sides of the base gasket. Put the saw together then take it to a saw shop and have them run a leak down test on it. It may cost a couple dollars but least you'll find the problem. I put one of those big bore kits on a ms460 for a tree company even though they are junk they got 2 years out of it. Idling for 2 to 3 minutes is to long it's like any air cooled motor at idle it's building more heat than being shut off. The flywheel forces air through the cooling fins more at high rpms than low rpms. idling for 30 seconds is the tops I would do especially on a after market big bore kit
No problem anytime I work on saws day in and day out. That sealant works the best I have found. Fuel and oil won't break it down wear some gloves when you apply it because you won't get it off your hands for weeks
It’s junk! Not necessarily. I had a 361 kit saw that did basically the same thing. I had to drive the piston out of the cylinder. I had a bent connecting rod and a grenaded piston. I had aluminum parts all in the crankcase. The cause was that Farmertec had not relieved the skirt on the piston to miss the counterweights. It was not hitting the counterweights but it was kissing them and after seven tanks it broke. I split the cases and replaced the broken parts. I did modify the new piston skirt to clear the counterweights. I now perform this check on all kit saws. My cases and bearings were fine. I just cleaned them up, put in a new crank, seals, piston and cylinder. It has 10 tanks on it, now, and it runs just fine.
I thought about maybe switching to Husky, but the closest dealer really is no help for service, and has to order all parts. Stihl dealer is more convenient has most parts or gets them in a day. Plus its been 4 years sense the last problem. So I got my moneys worth. The Husky does start easier though.
If Linda's willing to pay.. Go for rebuilt parts ! LOL. No matter what brand, after a wild, they will puke out some bits and bytes.. Keep us updated and best regards -Yves
The kit is only $140 delivered. A new MS461 is $1000. Linda wanted to try the kit. If it fails to start, Bibbyman2 wants some of the parts for his 044.
Intake side. My bet is you dropped the circlip on the intake side which grenaded the piston. If it was running at the time you probably need to split the cases and replace the crank and seals, too, in addition to the cylinder and piston. The connecting rod is probably bent with that much damage to the piston.
let me guess the piston clip came out got between the piston and cylinder? aftermarket stuff is garbage. the only one thats good is meteor or oem. thats all i use i have tryed that garbage it always comes back every time. JUNK
I keep all my repair/assembly tools in a plastic tote. It has everything I will need to take a saw, apartassemble a saw or maintain a saw. I hate having to walk out to the shop to get a specific tool, so I just throw it in the tote. The tote weighs about as much as one of my saws and my saws are not little saws it it has just about every tool I will need for a saw. Limited use tools are kept in my roll away in the shop.
Nowadays, try the bigger Echos, or Dolmar/Makita, Husqvarna, Jonsered. IME, stihls are overpriced and over-rated. Current ones are a bear to work on; e.g. 441CM. Thirty-day warranty not a real confidence-booster. Land Trust lads I volunteer with have a 441CM. Just past 30-day warranty, it sucked a 1/8" steel sphere in the exhaust between piston & port edge. Lunched both. Dealer said "Sorry, no coverage. Can't fix it. We can sell you another for $1K.) I got sucked in to R&R p&c. Never again on Rube Goldberg POS like that. (Love my 576XP-AT and Dolly)
All we have locally is ripoff dealers, of anything. Neither is a problem, if a saw is well designed & built and you can give it basic cleaning & feeding, routine checkover. IMHO. IME almost all saw maintenance goes into keeping chains sharp. Bet you can relate to that! Dealers I buy from are 100-200 mi N of me. 59 cc Echo can be had at HD, ditto used rental Dolmar/Makita 64 cc. Fan of your work, here, Al.
Thanks for watching and commenting. We have been in business for 24 years and have only had to hire the Stihl Dealer to do a Leak Down Test on this saw. Everything else we have done our selves. Thanks for letting me know you enjoy the Videos.
Scoring on exhaust side it's run lean. The saw is not tuned correctly. Second failure better do a leak down test and see if the crank seals are wasted from the first failure. Invest in a tach it will help with tuning get you close and then tune it in the cut
Thanks for the information. I have a Brigs and Straton viber-tach with the wire that shakes. Is that going to be accurate enough ? it does read to +15,000 rpm.
You can't put aftermarket piston and cylinder kits in the coating comes off the cylinder I am a stihl tech and a lot ove people do that on expensive saws it doesn't last trust me
VideosByAl So true,,, when the things flying through wood and the sudden stop happens,,, you're mind goes blank,,,, specially when u pull the cord and it doesn't. Then the blank turns into dollar signs. Going out,,, not coming in. Never pulled one down that far but after seeing the amount of debris in crankcase, unless you do a total pull down and check every speck of it I'd be leary to rebuild. Good luck.
I finished the rebuild , but must have torn the intake boot putting it back on. Ran a half tank of fuel threw it while it was lean. I needed a saw that day so I bought a MS461. This MS440 is in a box on the shelf. You can buy the power head for $300. It needs an in take boot.
The piston is fine, but there was a slight scuff on the cylinder wall. I would recommend honing the bore to put the cross hatch back in. I’ve seen a lot worse.
I rebuilt the saw, but tore the rubber intake installing the carb. Ran it for maybe 5 minutes. Check out this video of the light scratches. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-d0vRdQ2hsKY.html I boxed it up for another guy but his check has not arrived. $325 boxed up . UPS to Michigan was $23. I have pics of the boxed up saw I can email you. Leave comments on the private video.
The new Big Bore Kit showed up Yesterday, so I'll work on getting a video put together. Sad thing is it took longer to edit the video then to shoot the raw footage. Windows10 and our editing soft ware don't get along.
I have found Windows 10 to be mostly a pain in the butt too. Wish I could go back to the previous system but have been told by computer geeks I know that Microsoft has made Windows 10 the basis for a lot of future things. Bummer.
I am a stihl tech I work on them every day those aftermarket cylinders are junk the coating comes off people by them because thay are cheap but you pay in the long run trust me people do that with the ys420
You would think so, but it appears there is only miner damage in side. New Big Bore Kit is only $140.00 delivered. I'm going to risk some of Linda's money . Stay tuned.
John, I think the life of any cylinder combo is how you tune it and how you run it. I tune mine, reasonably rich, and run 40:1 and I have not had one problem with my aftermarket cylinders or pistons, not discounting my screwups. Sure, I would like to have a bunch of thousand dollar saws but I do not.
U got that right. Prob. overheated since he never blew the wood outta it lol. Come on Al, blow it out when ur done 4 the day...Air compressor is ur sawz best friend...
