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Parts Question

    Andrea Hand
    I am installing a new throttle trigger,throttle lockout, and...escalated
    Parts Question posted February 21, 2014 by Andrea Hand 
    3176 Views, 2 Comments
    I am installing a new throttle trigger,throttle lockout, and spring on my 450 Husqvqrna chainsaw. How can I get instructions on how to do this? I believe I have put the spring in backwards perhaps. Could someone provide instructions with a photo?
    Thank you.
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    • Karla


      I have Not changed those parts on a Husqvarna 450, however I did recently change those parts on a similar handle for a Poulan, and it was relatively easy. If you do not have an IPL drawing for your Chainsaw, I would definitely recommend downloading one, Its in a "PDF" format, so you can then enlarge the picture which will help.


      I am not sure what model year your model 450 chainsaw is, but hopefully this will be close.

      Steps of Instruction, based on IPL drawing:

      1. Remove the one screw in the handle on the left side

      2. Remove the cover plate on the right side of the handle (See IPL drawing/ diagram) it should pry out.

      3. Remove the pin ( about a 5/32 ) with a drift pin punch and tap gently with a hammer (pin should push completely through either direction).

      4. The "throttle lockout" ( part #  6 from diagram) should lift out from the top side of the handle

      5. Disconnect the throttle cable from the trigger, (Note:there will be tension on the cable which comes from the carburetors throttle spring)  but the cable with a little pull should move about a 1/2 inch when pulled on.

      5. The "trigger" and "spring" (Part # 4 & 5) should pull out from the bottom of the handle.

      Now, to put it back together reverse these steps, starting with step 5. (Note from  a enlarged "PDF" drawing observe the direction the spring is wound and insert it into the trigger that way).

      If your having difficulty engaging the throttle cable into the trigger, you might try removing the carburetor cover so that you can get access to the carburetor linkage and then blocking or holding the throttle linkage with a small screwdriver so the throttle cable is fully extended.

      Also, before step 3, make sure you get the "trigger" and the "throttle interlock" pin holes  properly aligned , before trying to tap the pin back in place.

      I hope this helps, also when I did the Poulan, I did a dry run of just holding (parts 4, 5, & 6) together in my hand so that I understood how the spring works and how it interlocks, before trying to put it together inside the handle.

      Please let me know If I can be of any additional help, and let me know if it works.

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

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      • Andrea Hand

        Karla, Thanks to you I got the job done.  I really appreciate your help.  Thanks again.

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