Husqvarna 545 auto tune

[a. palmer jr.]

I have a 545 Husqvarna that I'm having trouble getting it to idle for very long. When you start and run it for awhile it may idle for 4 or 5 seconds then it will die. Is there a way I can get it to idle without hooking up all the software and cables which I don't have?

 

[champion221elite]

I have a 545 Husqvarna that I'm having trouble getting it to idle for very long. When you start and run it for awhile it may idle for 4 or 5 seconds then it will die. Is there a way I can get it to idle without hooking up all the software and cables which I don't have?

Has the weather changed significantly since the last time you ran it? Assuming you have fresh mixed fuel in the tank? Try doing the cold start procedure and let it run for 30 seconds without bumping the throttle. I had to do this with my 555 AT last week. Ambient temps in the 20's is a big difference from 80's when I ran it last July.

 

[a. palmer jr.]

Has the weather changed significantly since the last time you ran it? Assuming you have fresh mixed fuel in the tank? Try doing the cold start procedure and let it run for 30 seconds without bumping the throttle. I had to do this with my 555 AT last week. Ambient temps in the 20's is a big difference from 80's when I ran it last July.

I just got the saw today (to work on). It has fuel in it but I'm not sure what kind. Another fellow was looking at it, don't know if he did anything to it. Should I run it at fast idle?, it wouldn't run 30 seconds at slow idle.

 

[ammoaddict]

I just got the saw today (to work on). It has fuel in it but I'm not sure what kind. Another fellow was looking at it, don't know if he did anything to it. Should I run it at fast idle?, it wouldn't run 30 seconds at slow idle.

That's what it says in my owners manual. Start and leave in fast idle for 30 seconds before you touch the throttle. It also says to set fast idle everytime you start it when warm. It helps prevent the infamous bog.

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[Andyshine77]

First thing I would do is put know good fuel in it. No help, than you'll need to hook it up, sometimes a refresh or update of the firmware will solve these problems. If that doesn't help you need to do a vac/pressure test, than have a look at the carb clean it and make sure diaphragms are pliable. Still a no go, and everything else is in order, new carb is in order.

 

[a. palmer jr.]

First thing I would do is put know good fuel in it. No help, than you'll need to hook it up, sometimes a refresh or update of the firmware will solve these problems. If that doesn't help you need to do a vac/pressure test, than have a look at the carb clean it and make sure diaphragms are pliable. Still a no go, and everything else is in order, new carb is in order.

We don't have the equipment here in this backwoods shop of mine and am too old now to contemplate getting it. I just though there might be a low tech way of seeing if anything is wrong or maybe just do what was said earlier about running at fast idle for 30 seconds or something of that nature. If I can't get it to run reasonably I'll just return it to the shop I got it from and tell them I can't do anything for it...I will mix up a new batch of fuel and try it. I can always use the old fuel in my Lawn Boy...

 

[Andyshine77]

We don't have the equipment here in this backwoods shop of mine and am too old now to contemplate getting it. I just though there might be a low tech way of seeing if anything is wrong or maybe just do what was said earlier about running at fast idle for 30 seconds or something of that nature. If I can't get it to run reasonably I'll just return it to the shop I got it from and tell them I can't do anything for it...I will mix up a new batch of fuel and try it. I can always use the old fuel in my Lawn Boy...

You can't get the equipment anyway and even if you do you won't be able to use it without having a dealer login. Perform all the normal diagnosis as you would on a normal saw, if nothing help and everything checks out, most of the time this all will require a new carburetor.

 

[a. palmer jr.]

You can't get the equipment anyway and even if you do you won't be able to use it without having a dealer login. Perform all the normal diagnosis as you would on a normal saw, if nothing help and everything checks out, most of the time this all will require a new carburetor.

Yeah, I forgot. That stuff is proprietory sp. They kinda want it to be dealer-only serviced...

 

[Andyshine77]

Yeah, I forgot. That stuff is proprietory sp. They kinda want it to be dealer-only serviced...

They want you tied to the dealer, just like auto manufacturers.

 

[a. palmer jr.]

They want you tied to the dealer, just like auto manufacturers.

Exactly!

 

[Ozhoo]

545's and 550's seem to benefit from adjustment of the mystery air bleed screw. 1/4 turn out makes a world of difference. Somewhere on here is a thread on it.

 

[Andyshine77]

545's and 550's seem to benefit from adjustment of the mystery air bleed screw. 1/4 turn out makes a world of difference. Somewhere on here is a thread on it.

Yes absolutely I forgot about that, definitely worth a shot.

 

[a. palmer jr.]

545's and 550's seem to benefit from adjustment of the mystery air bleed screw. 1/4 turn out makes a world of difference. Somewhere on here is a thread on it.

I just got done doing that, haven't started the saw up yet, working on another 390 stihl right now. I think I flooded it last time I tried so I'm letting the 545 sit for a while. Seems all of a sudden I have plenty of saws to work on after going most of the Winter without much going on...

 

[a. palmer jr.]

I went out and started the 545 today and let it run on fast idle for around 30 seconds or so but it still wouldn't idle. I did put in fresh fuel, non ethanol 91 octane mixed at about 40:1 with good Echo oil.. I tried it a second time and although it started okay it just wouldn't idle. I'm pretty sure the previous owner used ethanol in it like everyone else around here does...I guess we're fortunate he didn't straight gas it like about 10% of them do...

 

[Andyshine77]

You'll need to make a fee good cuts for the system to reset. I really am thinking the saw has an air leak so don't run it too much.

 

[chipper1]

I went out and started the 545 today and let it run on fast idle for around 30 seconds or so but it still wouldn't idle. I did put in fresh fuel, non ethanol 91 octane mixed at about 40:1 with good Echo oil.. I tried it a second time and although it started okay it just wouldn't idle. I'm pretty sure the previous owner used ethanol in it like everyone else around here does...I guess we're fortunate he didn't straight gas it like about 10% of them do...

How do you know he didn't straight gas it, what's the compression at, did you pull the muffler and look at the piston.
What yr is this saw?

 

[a. palmer jr.]

I'm pretty sure the saw doesn't have an air leak because it doesn't seem to stumble or idle fast like some that have air leaks do. The problem here is it just idles slow and dies. If you hold the trigger on slightly you can get it to run at near idle but when you let off completely it will finally die. I have a log outside my garage so when it warms up a bit I'll go out and cut a couple of cookies with it. I may sharpen the chain first, looks like it needs it. I've not checked compression or pressure/vacuum yet nor do I know the year of the saw but it's not too old. The only thing I've done so far is change the fuel in it and turn the air bleed screw out 1/4 turn. The saw did start fairly easily yesterday when I tried it so what I did helped a little bit..

How do you know he didn't straight gas it, what's the compression at, did you pull the muffler and look at the piston.
What yr is this saw?

The fuel that I drained out of the saw had oil in it, that's all I know about that. The saw was a trade in at a local shop so I don't know the person who owned it before the shop got it...

 

[Andyshine77]

Careful the AT system will do funny things to compensate for air leaks, they don't behave the same, this has caused a many AT saws to burn up. Bob seems to be an advocate of vac testing any AT saw with running issues. Plus these saws are known for air leaks, I've dealt with a few of them myself, the transfer covers and intake boots.[emoji111]

 

[chipper1]

Careful the AT system will do funny things to compensate for air leaks, they don't behave the same, this has caused a many AT saws to burn up. Bob seems to be an advocate of vac testing any AT saw with running issues. Plus these saws are known for air leaks, I've dealt with a few of them myself, the transfer covers and intake boots.[emoji111]

Exactly.
When my 576AT had a defective decomp it was still 4-stroking and sounded fine. I have videos of it running and you can't even tell. The only reason it was found is because the muffler was removed for a mod and then you could see slight scoring.

I'm pretty sure the saw doesn't have an air leak because it doesn't seem to stumble or idle fast like some that have air leaks do. The problem here is it just idles slow and dies. If you hold the trigger on slightly you can get it to run at near idle but when you let off completely it will finally die. I have a log outside my garage so when it warms up a bit I'll go out and cut a couple of cookies with it. I may sharpen the chain first, looks like it needs it. I've not checked compression or pressure/vacuum yet nor do I know the year of the saw but it's not too old. The only thing I've done so far is change the fuel in it and turn the air bleed screw out 1/4 turn. The saw did start fairly easily yesterday when I tried it so what I did helped a little bit..

The fuel that I drained out of the saw had oil in it, that's all I know about that. The saw was a trade in at a local shop so I don't know the person who owned it before the shop got it...

All the ones I've seen that were burnt up from being straight gassed also has mix in the tanks except the one I straight gassed .
I would inspect the impulse line if this saw has one, kinda sound like that could be an issue. If it doesnt have a line then check the port for blockage, this could be the case if someone else worked on it before you.

What do you think @brad ruch lol.

 

[brad ruch]

Exactly.
When my 576AT had a defective decomp it was still 4-stroking and sounded fine. I have videos of it running and you can't even tell. The only reason it was found is because the muffler was removed for a mod and then you could see slight scoring.

All the ones I've seen that were burnt up from being straight gassed also has mix in the tanks except the one I straight gassed .
I would inspect the impulse line if this saw has one, kinda sound like that could be an issue. If it doesnt have a line then check the port for blockage, this could be the case if someone else worked on it before you.

What do you think @brad ruch lol.

I would suggest getting it hooked up to the software.it may show error codes for stopping.i had the same problem on mine and had the software updated.i also put a new plug in it.i can tell ya these AT do not like dirty plugs at all.

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