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Service & Maintenance Question

    reuven spero
    Husqvarna T435 - having two problems right now: 1. chain...escalated
    Service & Maintenance Question posted January 29, 2014 by reuven spero 
    6165 Views, 25 Comments
    Question:
    Husqvarna T435 - having two problems right now:

    1. chain keeps loosening, like, really fast. I checked the parts manual - everything is there. cranking down hard on the nut - yes. chain is not new, but sharp. bar just seems to be moving in. how can i fix this?

    2. getting lots of blue smoke after operating for a few minutes, like there is oil leaking onto something hot inside. I don't think this is oil leakage in the pistons, b/c power seems to be ok. on the other hand, i think the smoke may be coming out of the muffler hole. how do i diagnose this?
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    Answer

    • Karla

      Reuven,

      First I understand that you checked all of the Parts for the brake/ clutch cover and the bar mounting parts to the chainsaw, Did you compare the parts to the IPL Parts list, If you were missing one of the two oiler plates (Iems # 2 & 5 in the attached file) , you may not be getting enough tension from the bar nut on the cover. The bar and chain have to be sandwiched between those plates and then torqued down, or at least fairly tight with a scrench. The other possibility is something is causing the bar bolt or bar nut to loosen up like engine vibration. You could try as a test putting a little "Mild strength" Thread lock compound on the bar bolts threads, "Do Not use extra strength lock tite", since you do want to take it off, Locktite is available at most automotive stores. This test will determine if its loosening up from a little vibration.Oh also I would clean the bar nut and bolt real good with some carb cleaner so there is no oil on the bar bolt, this will also help add some mechanical resistance and increase the friction of the bolt and nut.

      Here is a link to an IPL drawing and parts list: /images/ddoc/HUSI/HUSI2009_AAaa/HUSI2009_AAaa_21_.pdf

      Next, the problem of the engine smoking: This can be caused by improper Oil to Fuel mixture, one test you could try is get a can of fuel pre-mix for the recommended 50:1 ratio, available at most stores now that sell chainsaws and parts. Run a can of that through the saw, and see if it still smokes. The second possibility is that you have a carburetor problem, which could be just an adjustment, If the "L" needle is set too "Rich", then the engine can't get rid of all the fuel and oil, so it smokes, and yes the excess fuel and oil mix will come out through the muffler and you may even see a stain running down the outside of the hot muffler as it burns off. Your chainsaw probably has limiters on the "L" screw, but you may be able to turn it a (1/8-1/4 turn clockwise) , just remember where its set at before turning it, so you can put it back if it doesn't fix the smoke problem, just a small adjustment may fix the problem, try just an 1/8 turn clockwise.

      I hope this helps, Please let me Know if these tests work for you, and if I can be of any additional help

      PS. I am Not a Husqvarna Representative or an Authorized Repair Center, Just an experimental chainsaw person.

       

       

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      • reuven spero

        First of all, Karla, thanks for your prompt and knowledgeable reply.  I've yet to find a reliable service rep here - most of them just want me to buy a new saw..... what is an "experimental chainsaw person?"  Was that an auto-correct for experienced, or are you doing experimental stuff?

        Ok - both plates are there.  And when I check the nut (after I see the chain is loose) it is still as tight as when I screnched it down.  I am mystified by this problem - I don't see anything obviously out of sorts, and the problem started suddenly fairly recently.  I welcome any further ideas  you might have.  If you want me photograph it, I can do that. 

        I'll try the carb adjustment tomorrow.  Thanks for the idea.

        BTW, I saw that Nadav is having a problem starting his saw of the same make - Nadav being an Israeli name, and I'm in Israel, on the chance I might be able to help him, you can give him my email, if that doesn't violate any rules of the site.

        Thanks,

         

        Reuven

         

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    • Karla

      Reuven,

      I will pass your name on to Nadav, maybe you can compare notes.

      OK - In answer to your question "Experimental Chainsaw Person", That is the title I have given myself. I like to experiment with chainsaw engines, and have worked on a wide variety of different Manufacturers, I like the challenge especially when someone says "this is trash, and it will never run again". I have about Fifteen of those chainsaws, and they all run as good as new, maybe even better. Oh, also its sort of a disclaimer that I am Not an Authorized Repair Center. Lol. I have also gotten chainsaws from Authorized Stores and Repair Centers, who sold me really nice chainsaws as scrap, and they are now running. I remember one story about a Husqvarna 455, the Store said it was scrap because the engine was siezed up, one of the customers brought it back the same day after buying it brand new, the store gave them a New replacement chainsaw, and I bought the scrap one for parts. The Store said the individual must have run the saw with straight gas and No oil, I was kind of skeptical that really happened. Anyhow, I got the chainsaw home removed the muffler and the piston ring was stuck but I was able to move it 1/4 inch, I inspected the rest of the cylinder and piston and it was brand new, bright and shiney, no scoring not even a scratch. I put it back together, added some straight engine oil to the engine, and the engine pulled over with the starter cord, on the second pull the engine started, and I use the chainsaw all of the time. Lol. I think alot of times, as you stated the service shops don't want to bother, and hope you will buy a new chainsaw. Also Lol. and Enough about myself, and back to your problem.

      Bar and chain movement problem: I would check the following  additional areas: 1. The bar and chain tensioner screw, remove the bar and chain and turn the tensioner adjustment in both directions for its full travel, and make sure it turns freely, also add a little oil or lithium grease to the threads, it should move very easily for the full travel. I had a chainsaw that had a bent tensioner screw, and it felt like you were properly tensioning the bar but actually the tensioner screw was binding up and never tightening up leaving the bar and chain loose. Also Never over tension the bar and chain always leave it just a little loose before tightening up the bar nuts, and always check that there is a little slack in the chain, very important. 2. Check the condition of the drive sprocket, it should not be worn or have any deep grooves in the sprocket teeth, I had another chainsaw, that when I tensioned the saw it would tension correctly but when I ran the saw it would loosen up, what was happening is the sprocket had a worn groove in the teeth and needed replacement. When I tensioned the saw the chain was on the good part of the teeth and not in the groove, when I ran the saw the chain dropped down into the groove, and became loose. This may sound similar to your problem, and I also thought at first that the bar must be loose, but it definitely was Not, Check the condition of your drive sprocket.

      Please let me Know what you find, also If you are going to replace the drive sprocket, I would definitely recommend "PowerMates Rim and Drive Sprocket", Made by Oregon bar and chain company. This sprocket system will both solve and prevent alot of problems.

      Again, I hope this helps!

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    • reuven spero

      nice story, Karla, and interesting.  and that's why, when I hear the words, bud you need a new saw, I start looking elsewhere, unless they can show me unequivocally that the goose is cooked.  even then, i'm not convinced unless two different places tell me that. had a story along those lines with a friend's 350 - one place called it dead, the other repaired it for $50.  As far as I know, it's still chuggin.

      ok, the moving chain:  cleaned everything again, real well, put on a different chain, marked the place on the bar, and cut for about 15 minutes, and the bar stayed in place, the chain just right.  don't know.  maybe the chain was the problem, but I don't see how.  I sprocket showed wear, but nothing unusual.

      blue smoke - the L was already turned almost all the way already.  don't think i got another 1/8 out of it even.  i don't think it is the gas/oil mixture - i measure pretty carefully.any other ideas aside for oil getting past the rings (are there rings on these engines?)

      again, thanks for your help.  finding expert advice is one of the nicest things about the internet.

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    • Karla

      Reuven,

      Yes it could be a chain problem, the reason being the drive links which fit into the bar are ground when manufactured into a distinctive shape. (Note: I would probably try to draw the shape here on the screen if i could - Lol), You can see the shape of the drive link by either looking at a chain thats not installed on a chainsaw or by pulling up on the chain till its out of the bar groove. The drive links shape has two purposes, the link is curved so it will go around the bar and stay in the bar groove, and also has a small notch in the drive link and this is to engage the drive sprocket gear, so that the sprocket can drive the chain.

      Sometimes the drive links can become worn and even change their distinctive shape, (Note: They can be dressed with a round file to correct the notch of each of the drive links, see Link to "The complete Oregon maintenance and Safety Manual", specifically drive links), This would be the opposite effect of the drive sprocket gear becoming worn, and developing a groove, but may have the same result of being loose after running the chainsaw.

      /pdf/pro/service/maintenance_manual.htm

      After you down load the link, just page down and  go to pages 70 - 72 which will explain drive links. Actually the entire "Maintenance and Safety Manual" is real good reading, and you will learn alot.

      I hope this helps!

       

       

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    • Karla

      Reuven,

      I just typed a long page to you and lost everything - Ugh.

      Anyhow, If you go to page 33 of your Operating Manual, you will find directions on how to locate and remove your muffler on your T435.

      It is possible that your chainsaw is smoking because of a carbon blockage at the exhaust port of either the muffler, spark arrestor screen (a replaceable item on the muffler) but can also be cleaned, or a carbon buildup in the actual exhaust port.

      You will need to remove the muffler, and then carefully inspect these area's, make sure the spark arrestor screen is very clean, any black carbon build up will block the engines air flow.

      The blockage of carbon will reduce the air flow through the engine, and hence the engine will run "rich" and give you the same symptoms, and smoke, since you have tried everything else, this is where I would go next.

      Again, I hope this helps, and give me a shout If you need help.

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    • reuven spero

      getting the cover off the muffler was harder than expected, but I didn't break anything, I don't think.

      but removing the muffler - see, this is where experience comes in. The screws just wont budge.  Two are the star shaped heads - I have the right screwdriver for them), two are small bolts.  I sprayed them and left them and hope it helps.  What do you do in situations like this?

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    • Karla

      Reuven,

      Yes, They can be tough to remove but definitely worth doing, and making sure there is no carbon in the spark arrestor, which you will have to remove the muffler.

      Soaking the screws may help with some penetrating oil, I would definitely try that first. Next try hitting the center of the screw/ bolt head with a center punch or a pin punch, But do not hit very hard with the hammer. Also would probably recommend a lighter hammer, like 8 or 16 oz, ballpein hammer. If the hammer is too heavy you may be over zealous with the tap on the punch. But give it a couple smacks with a lite hammer to a punch.

      The reason the bolts are tight is they are torqued but actually only about 4.9 - 7.8 N-m, so not really that tight, the second problem is the disimilar metals the bolts are hard steel, and the engine is cast aluminum, so you get a little aluminum corrosion between the dissimilar metals.

      When you do get them out, I would recommend new bolts, I also put a little "Neversieze" on the new bolt threads which will make it easier the next time. to remove the bolts. I hope this helps.

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    • Karla

      Reuven,

      Also, If you try the penetrating oil, and you try tapping on the bolts (which is to loosen any corrosion between the dissimilar metals), then it may be time to get some help from a Machinist friend or a small shop, that can use some other tricks to remove the bolts.

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    • reuven spero

      work has gotten in the way in the meanwhile - i'll be getting back to the saw next week, i hope.  but yours is a good suggestion.

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    • reuven spero

      and that's what I did - took it to a workshop - the fellow was the israeli equivalent of a "good ol' boy" - and he got the screw off for me.  I asked him what the secret was, and he said likely I was using a 25 when it really was a 27, said he's seen this happen often and even happens to him, if he's not being careful - they look a lot alike. 

      by the time he got it disassembled, he was interested in the  problem also and went ahead to disassemble the muffler and check out the screen - he told me he'd be shocked if it were clogged, because in his long experience with Huskies, that doesn't happen much.  he said he knew the 435t real well becasue when the previous model came out he had made some design change suggestions to Husqvarna which had been adopted in the 435t.  Good ol' boy talk.

      while the muffler was off i took a peek at the piston, and it was as smooth as if it were brand new.  he said the saw didn't look like it had been run much (it actually has, I've had it for almost 2 years and use it fairly regularly), and complemented me on the upkeep - first time in my life that has happened to me!

      anyhow he said I should go back to the standard carb setting first to see if that made much difference.  he said the standard setting is high, one turn, low - one and a quarter turn.  this is so?  what do you think?

      in any case, although he does have that "i created the internet" attitude about him, he seems more on the level than any other workshop I've found in this country.  Took no money for his time, and was cheerful and helpful.

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    • Karla

      Reuven,

      Glad you got some good help nearby, I looked at the service Manual for the T435 and it says for a New carburetor setup or if replacing the high or low needles, then the recomendation is H = 2  turns off of seat, and L = 2 1/2  Turns off of seat. I have clipped the actual text, and enclosed it in the attached file.

      But the problem when your adjusting the carburetor is that these setting will probably get the chainsaw started but is "Not"  where the chainsaw is left after it is tuned up.

      My recommendation would be to start your adjustment from where it is currently set since the saw does start and tweak it a little from there, because If nothing has drastically changed with your saw then you should not have to  move it very far from where it is set. Also to make any adjustment outside the range of the limiters means you will have to remove the limiters, and since they sometimes get destroyed removing them you will have to have replacements.

      It is possible that something has changed inside the carburetor which is now causing the carburetor to be running "Rich" and resulting in smoking, there is a fuel/ pump diapragm and also a metering diaphragm inside the carburetor. The metering diaphragm has an adjustment which is the metering lever and needle adjustment internal to the carburetor. If that adjustment changed due to  a metering diaphragm problem then, that will result in different settings for your "L" and "H" adjustments. Anyhow that means your "L" and "H" adjustments are Not a absolute hard fact.

      The Key ingredient is that the Chainsaws RPM's are set correctly, I use a digital tach to check RPM's, and Old school mechanics could listen to an engine and determine the correct RPM's. So here is what the T435 should be set to: Idle or "L" adjustment  = 2900 RPM's, Clutch Speed engagement  = 3800 RPM's, and High Speed (WOT)  or "H" adjustment = 12,500 - 13,000 RPM's.

      Its important that your Idle speed "L" adjustment not be set too high or your clutch will always be engaged and the chain will be running all of the time, which is obviously not good.

      I hope this helps, and sorry to be so wordy.

      PS. I was really hoping you would find a partially plugged spark arrestor, and yes, Not to contradict your mechanic but I have found a few of them, and had to clean them to fix the chainsaw. Anyhow its good that you were able to get the bolts off, and removing the muffler checking for carbon build up is a good test to perform periodically, along with taking a peek at the piston, piston ring and cylinder walls through the exhaust port. It also sounds like your engine is still in great shape, and you just need a little carburetor work.

       

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    • reuven spero

      i don't mind you being wordy - every paragraph you write, i learn something.

      look,  i have an analogue tach but I haven't the faintest idea how to use it.  i'll do a youtube search and see what i can find.

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    • Karla

      Reuven,

      Actually U-tube is a great idea especially watching a few individuals tweaking their chainsaws. It really is a dificult thing to be put into words, and you kind of have to do it, just be careful you don't run the RPM's up too high, some of the chainsaws will run way faster than the recommended settings but that is Not necessarily good to run them at the highest speeds, they need to be tuned a little bit "rich" but not enough that they constantly smoke. Too "lean" and they may seem to be running faster but the engine is not getting enough oil,  the engine will run hotter too, and then you have the possibility of damage to the cylinder, so it really is important to get it tuned correctly.

       

      Again I hope this helps, Please give me a shout and let me know your progress.

       

       

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    • reuven spero

      hmmmmm.... my tach doesn't do two stroke engines.  i found inexpensive tachs on ebay/amazon, but some of the comments made me think that these tachs would not work wel lfor a chainsaw.  they don't sound difficult to use - just wrapping the lead around the spark plug wire a few times.  although if i need to check clutch speed, do i need a laser tach?  can you recommend one?

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    • Karla

      Reuven.

      Here is a link to one, which looks very similar to mine and works on 2 stroke engines.

      http://www.ebay.com/itm/Hour-meter-tachometer-tach-digital-LCD-KAWASAKI-atv-motorcycle-generator-mx-utv-/111257572770?pt=Motorcycles_Parts_Accessories&hash=item19e777d5a2&vxp=mtr

      Its an "Hour meter - tachometer", I have seen these sold at many on line sources, It has a single wire that you wrap a couple turns around the plug or spark wire lead.

      I hope this helps.

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