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    Eric V.
    Husqvarna 440 Gas Tank Vent/Breather Help Needed. I have...
    Service & Maintenance Question posted October 19, 2015 by Eric V., last edited October 19, 2015 
    4709 Views, 10 Comments
    Question:
    Husqvarna 440 Gas Tank Vent/Breather Help Needed.

    I have a Husqvarna 440 chainsaw that is pretty much brand new and it was not running well this weekend. It would start and idle fine but stall out after a couple of minutes under load. If I opened the gas tank lid it would work fine again for a few minutes. After some research I can tell I need to replace or clean the gas tank vent/breather. I find the part online to order but I can't find where it actually is on the saw. I took the top cover off and the starting cord assembly but can't find it anywhere. Can anyone let me know where it is (or better yet post a picture of where it is) so I can replace it.

    Thanks,
    Eric

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    Answer

     

    • Eugene Rounds

      The vent in location on the RH side of the fuel tank. In order to replace the vent you would need to remove the fuel/handle assembly.

      See area circled in orange.

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    • Eric V.

      Thanks for the reply and picture.  I had seen this diagram when I was doing my research but could never find where the heck that little part was.  I guess the explanation is that I have to take the whole saw apart to get to that piece.  Seems like a kind of big hassle... any idea how involved it is to remove the fuel/handle assembly?? I'm a bit surprised that there is no easier access to something that seems to be a typical problem part.

      Thanks,

      Eric

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      • Eugene Rounds

        Not really all that hard; Just to mark which fuel hose is which. Note: "dismantle" means "remove" here.

        From the service manual>

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    • Karla

       

      Eric,   

      I agree with you that the fuel tank vent is at difficult location, and prone to getting plugged with debris. However I must admit, that I have Not replaced too many fuel tank vents, they usually last a long, long time. I am also Not sure why that little vent is also, so pricey I think they are usually around $8-$9.00, and I can purchase a couple fuel filters much more reasonable.

      Anyhow, One other thought, I have seen on some Husqvarna chainsaw models where they have a short piece of fuel tubing fastened on the end of the fuel vent, extending the vent up into the carburetor compartment. Not sure If that is feasible to do on your model, but it might keep dirt and debris from getting into the vent. And with the extended piece of fuel line into the Carb. compartment, it should be kept cleaner located there.

      Just a thought, and I hope this helps.

      Karla

      PS. I am not a Husqvarna Representative or a Repair Service, Just an experimental chainsaw person

       

       

       

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    • Eric V.

      Thanks for all of the info and advise... I just have to commit myself to taking things apart to access the vent.  I may just try blowing everything out with my compressor and hope that solves it the easy way.  Like the idea of adding a small tube to move the vent to a cleaner and easier to access location.

      Thanks again to all...

      Eric

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    • Eugene Rounds

      I don't think you will be able to move the vent itself to a different location but the length line to carburetor area could improve things. As Karla said I too haven't seen many plugged vents.

      Karla I have seen the system your thinking about but tank vent is mount in the carburetor box using an Echo style fuel vent on the end of the line connected to a nipple on the tank top RH side. It stood out as that where a customer had a fuel leak last year when the line came off. I wish I could remember which one it was but after working on over 100 different chainsaws this year but I am drawing a blank which it was.

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    • Karla

      Eric,

      Just one more thought, before you take apart your chainsaw.

      If you have access to an old turkey baster or a syringe type bulb (Available at most dollar store for maybe $2.-), you can test your vent without taking your chainsaw apart, by performing the following:

      1. Remove the fuel from the tank and put the cap on snug.

      2. Remove the fuel line connection at the carburetor

      3. Fasten the syringe bulb , you may need an additional piece of tygon tubing and a tubing connector (available at most auto stores and some big box stores) you need a fairly good air tight connection to the fuel line

      4. By squeezing the syringe bulb a few times see if you can create a vacuum on the tank by drawing air from the fuel line. If you can create a slight vacuum then yes your fuel vent is plugged, and If you can't then your vent is OK.

      By the way, the correct tool that would make this easier is a "MightyVac" pressure/vacuum pump. (by the way its a great test tool for testing small engines especially if you are working on a few engines but very pricey.) 

      But definitely Not worth purchasing for this one time application, just use a syringe to try and draw a vacuum, it may take a few really good squeezes, but it will work.

      Again, I hope this helps

      Karla

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      • Eugene Rounds

        Karla, Yes the pump vacuum/pressure version is well worth the price if your working these engines professionally. As not only tank need vacuum testing they also pressure testing. I got one on my Christmas wish list already sent to Santa this year. But currently I use a large 200cct syringe for pressure vacuum tests of this cube carbs and other carbs.

        I got to get one so I accurately test crankcases via the leakdown tests.

        Also If you don't have of the 435/440 workshop manual I can send you a copy.

         

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    • Karla

      Eric,

      You also really could leave the fuel in the tank and see if you can extract the fuel easily by using a syringe, the same way connected to the carb line but it could get a little messy with gasoline, and would recommend doing it outside. If the fuel comes out thru the fuel line from the tank easily then again your problem is Not the fuel vent.

      Sorry for being so wordy but I am trying think of the easiest way for you to test the vent.

      Karla

       

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    • Karla

      Eugene,

      I have a few of the shop manuals already including the 435/440. the 455, the T435 (arborist) , but I would like to find one for the 545/550 Autotune. I also would prefer exchanging items like that directly, and Not posting them.

      Thanks again for the offer, and If I can help you, I will be glad to try. Just send me a post directly to my mailbox.

      PS. I have also collected lots of neat stuff on testing engines with a MightyVac, and have done all of the different tests over the last couple of years. Now finding stuff on my computers that is an entirely different problem, I'm not the most file organized. Lol

      Karla

       

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