Chainsaws

Mark,

Here is some information that may help you, as far as the Ignition coil going bad previously, that sounds suspicious since that is a simlar symptom to the engine Not starting, and a lot of individuals think its an ignition problem that the engine won't start but its really a fuel problem like a flooded engine, so i wonder ? But I guess we will never really know. I have worked on alot of Autotunes, and I really like them however, you can flood the engines very easily by choking the engine, and then pulling too many times to try and get it started. If you have pulled the engine more than once or twice on choke, and it didn't pop or hear it try to start, then take it off the choke and go to the run position, and pull it rapidly 2-3 times. Also If I think I may have flooded the engine, then hold the trigger wide open for wide open throttle, and with it in the run position pull 2-3 quick good pulls. I hope this helps.

I would  check the primer bulb is working properly, besides checking that the lines are connected correctly which is very important, there is also a small rubber check valve inside the primer bulb, and I have seen them go bad, and then the engine won't run. An easy check is pull both lines off of the primer bulb just remember which one was connected where. There will be a short connection on the back side of the primer bulb, and another connection which is a little longer, so use that as reference. Also Not easily seen and stamped into the black plastic of the primer bulb will be the word "IN". This is the connection that must come directly from the line connected to the carburetor. Anyhow, an easy test Is with both lines disconnected, push in on the primer bulb, and then with your pointer finger block the "IN" connection, and let go of the primer bulb. This is the suction side, and if you have a good seal with your pointer finger then the primer bulb will Not pop out, however If you do the same test to both connections, and it does not make a difference, then you have a bad check valve inside the primer bulb, and will need to replace the primer bulb.

I hope this makes sense, and remember to get the connections hooked back up correctly or it won't work either.

Karla

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

Mark,

Thanks for the clarification on your problem, and sorry to hear that you had both an ignition problem, and now a fuel problem, It is strange to see a chainsaw with both problems, the chainsaws that I have worked on its usually one or the other. Anyhow, just some information on Autotune, The carburetor can actually be worked on the same way as a standard, Non Auto tune carburetor, which means the carburetor has all the same basic parts inside. The difference is that on a standard carburetor you have a mechanical adjustment needle for the Low & High settings of the carburetor, and on an Autotune the needle valves have been replaced with very tiny electrical valves controlled by software programming. I hope that helps. Unfortunately the Dealer will most likely do just a replacement, which means he replaces the Autotune module with the carburetor. Has the dealer done an Autotune Diagnostic? to see if its just the electronics or Is it really the carburetor ? Some can do that If they have the diagnostic box, and its really a very easy test.Again they will probably just replace both together. I have Not had too many failures with the electronics, and its usually the same type of carburetor failure as a Non Autotune carburetor, which means something has gotten inside the carburetor, and it needs to be internally cleaned, or a metering diaghram, or fuel pump diagram inside the carburetor has failed or is not working properly. Again, Just a little xtra information, and hope it helps.

If I can provide any additional information, Please let me know.

Karla

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

Mark,

Thanks for the update again, and please keep me in the loop, If you have any future problems. I like problem child chainsaws, and solving problems, I call it my Chainsaw Forensic Diagnostis, and its just a hobby. If you have an Autotune questions, just fire away and I will be glad to try and help you or answer a question. Since you said you have done your own small engine repair that is excellent, and treat the Autotune Chainsaw the same way as a Standard Chainsaw, and diagnose the chainsaw the same way, I realize that the Autotune is that Unknown factor but I have Not really seen any problems with the electronics or software. Ocassionally they will do updates of the firmware/ software, and I'm not sure If there is a New one out right now for the Model 455. They can do some finite tweaking of the electronic valves If someone has for example a hot start issue, or a few other issues, but basically it works or doesn't work. And again I have Not seen any that don't work, its usually due to some other problem like a dirty fuel filter, or dirty carburetor, or bad fuel/ metering diaghram inside the carburetor. Again, I hope this helps, and I also hope your chainsaw keeps working in good order.

Karla

Mark,

I believe you would need to change the flywheel, Ignition coil, and carburetor to change it back to a Standard Non Autotune chainsaw.

The flywheel is special because the magnetic pole pieces are different along with the ignition coil which is compatible with the Autotune electronics on the carburetor. However what I would probably try, If your familiar with standard chainsaw carburetors, is purchase a carburetor repair kit, they are anywhere from $5 - $10.00, then thoroughly clean the inside of the carburetor removing the fuel pump side of the carburetor, and after cleaning, replace the gasket & fuel pump diaghram. Then do the same thing for the Metering side of the carburetor replacing the gasket and diaphram. Leave the Autotune Electronics in place, Do Not try to clean or do anything to that plastic module,  It can stay connected to the carburetor, so you don't have to take that module off the carburetor. IF you are Not Familiar with cleaning inside carburetors,  then I would suggest taking it to someone who can do the cleaning. I suspect that the Autotune is probably OK, since it starts and tries to run but possibly the fuel pump or metering diaphram has a problem. IF you can find a Dealer that has the Autotune Diagnostics, then you could have them check the software, and see If that part is working correctly, I would Not expect that it would be a big charge if any to check the Autotune software. 

I hope the above information helps, and If you need any additional information Please let me Know.

Karla

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

Please Keep me in the loop, as you discover what is wrong. If you remove the metering diaghram, don't forget to check the height of the metering lever.If the metering lever is set too low, then you could have a similar symptom to what you describe, you would have fuel to start the engine but then it would bog down,  If the metering needle is not open enough to supply enough fuel.

Just another thought.

Ugh, Sorry to hear your still having so many problems, Maybe Husqvarna will give you a replacement.

Please let me Know how it all turns out, I assume you have their Phone number and address.

Karla

Great News, and glad you perservered and are getting some results. Yes - I have heard of bad Dealers before, and I have also experienced it myself one time, and never went back. I needed some parts, two (2) piston rings for the same engine, and I was told by the Dealer they would be $25.00 each, I quickly ran out of that Dealers store.But, If you really don't know your sort of at their mercy. Anyhow, Glad you still have faith in Husqvarna. Please let me Know If I can ever help, I always like new questions, and I am definitely interrested in problems and results. Karla