Husqvarna 545 auto tune

[a. palmer jr.]

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 don't think anyone actually worked on this saw, they just looked at it and were kinda intimidated by it. I mentioned to one of the guys about adjusting the bleed screw and he didn't seem to know what I was talking about. That's how I ended up with it, even though I know very little about these auto tunes...One thing I did notice was when I ran it on fast idle the saw seemed to run a bit heavy on fuel mixture, not like the fast idle on my 346xp for example.

 

[Dylan Hazeltine]

If you're still having problems it may need to be "re-taught". Start it up and let it get a bit warm. Go WOT and hold it there, make around 7-12 long cuts at WOT (Don't let off even when you shift to a new cut.) Keep it at WOT under load for between 3-5 minutes and that should reprogram the carb for your altitude.

 

[a. palmer jr.]

If you're still having problems it may need to be "re-taught". Start it up and let it get a bit warm. Go WOT and hold it there, make around 7-12 long cuts at WOT (Don't let off even when you shift to a new cut.) Keep it at WOT under load for between 3-5 minutes and that should reprogram the carb for your altitude.

I was gonna try that just a few minutes ago, got my log ready went into the shop to get the saw and tried to start it and it wouldn't start...Can't understand it, the thing started yesterday just fine...

 

[Dylan Hazeltine]

I'm looking at a carb from a first gen 550xp right now, honestly, I don't see any manual adjustment on this thing anywhere. It may have to get the fuel setting reset at a dealer with the CST program.

 

[Tobystihl]

My experience with these when they won't tickover, but otherwise run fine is to replace the piston ring.

 

[Dylan Hazeltine]

Unless the thing got dropped in water and fried the carb lol... I just finished rebuilding one of those.

 

[Ozhoo]

I'm looking at a carb from a first gen 550xp right now, honestly, I don't see any manual adjustment on this thing anywhere. It may have to get the fuel setting reset at a dealer with the CST program.

Give this a read...
https://www.arboristsite.com/community/threads/anyone-know-about-this-550xp-fix.305230/

 

[Dylan Hazeltine]

It's good information, thank you. Just requires pulling the brass plug out of the carb body. Wouldn't help this one much though. It's trip into the water messed up the computer adjustment. Even with a reset with the CST software it went right back to tuning itself off.

 

[a. palmer jr.]

I was kinda afraid to use the primer bulb this time when starting for fear of flooding it again. Maybe tomorrow I'll try starting it differently and see how it does...

 

[Dylan Hazeltine]

The purge bulb shouldn't make it flood unless you have something not sealing properly in the carb. If it did flood out you could still have residual mix in the bottom of the crankcase.

 

[a. palmer jr.]

The purge bulb shouldn't make it flood unless you have something not sealing properly in the carb. If it did flood out you could still have residual mix in the bottom of the crankcase.

Yep, that's the way it's supposed to work. I tried using it once before and it didn't seem to start very good. Next time I tried it without the bulb and it started pretty good. Last time however it wouldn't start not using the bulb. I'll try again tomorrow using the bulb and see what happens. I can't pull very many times before getting out of breath because of a heart condition but I can give it six or seven good yanks unless it's a big saw, which this one isn't...

 

[a. palmer jr.]

I went out this afternoon and pushed the primer bulb three times, choked it and it fired right up. I kept it running while I managed to pull the log over so I could cut it and cut through it three times and must say the saw sounded great and cut through that approx. 18" log really well. I then tried to idle it down and it idled for a few seconds and died. I'm pretty sure ethanol is the culprit because that's what most put in their saws around here except me, nobody wants to buy the canned fuel either because of the cost, I make the 35 mile round trip to get real gasoline. Every year we go through this and I always tell then about the fuel but to no avail...I'll let the owner of the saw decide on the $100 carburetor.

 

[chipper1]

Why not put a kit in it.

 

[a. palmer jr.]

Why not put a kit in it.

Might try it later on after I ask the owner what he wants. On most of the saws I just buy a $12 new carburetor but can't do that with this one...A kit probably wouldn't help the idle unless I give it a good soaking first..I wish they'd at least put an idle speed screw on that saw...

 

[PV Hiker]

You may looked already at fuel filter, air filter, sparkplug along with hose ends fuel and impulse. Coil gap correct? All the wire connections tight not loose. You never know.....

 

[a. palmer jr.]

You may looked already at fuel filter, air filter, sparkplug along with hose ends fuel and impulse. Coil gap correct? All the wire connections tight not loose. You never know.....

You'd be surprised at all the things I haven't done to the saw yet, air filter seems okay, haven't looked at fuel filter but I did change fuel, don't know where the pulse hose is yet, haven't checked the spark plug or coil gap. I don't think I have a replacement plug for this one if it is bad, it looks kinda small. I just brought the saw over here to check the idle and off idle response but guess I'm gonna end up doing a lot more than I wanted to...

 

[Andyshine77]

Need to do an air leak test! I can almost guarantee it's an air leak or bad carb.

 

[a. palmer jr.]

Need to do an air leak test! I can almost guarantee it's an air leak or bad carb.

I don't plan on doing that much work on this saw unless owner wants me to, I have several Stihls over here to rebuild and can't spend much more time on this thing, wish I had my camera out in the shop so I can take pics of the saws I'm behind on...I know I won't be buying a new carb for it because of the price but like you said, it's a good possibility it could have an air leak. I'll let them do the air leak test if they want to do it, I do it on the Stihl saws I work on because I have all the blocking plates for them but not for other brands...

 

[Andyshine77]

I hear you, and with the intake tubes for the strato ports it takes a little more work to make the plugs for them. I finely got my 550 running correctly but it took some work, and this was a new brand new saw. The transfer seals leaked, the intake boot leaked because the carb was installed incorrectly. Last but not least when I got those issues resolved, the carb went bad on it's second thank of fuel.[emoji17] The first generation 550 is a POS. Sadly when they do run, they're wicked nice little saws.

 

[a. palmer jr.]

I hear you, and with the intake tubes for the strato ports it takes a little more work to make the plugs for them. I finely got my 550 running correctly but it took some work, and this was a new brand new saw. The transfer seals leaked, the intake boot leaked because the carb was installed incorrectly. Last but not least when I got those issues resolved, the carb went bad on it's second thank of fuel.[emoji17] The first generation 550 is a POS. Sadly when they do run, they're wicked nice little saws.

I noticed how well the saw ran, even given what might be wrong with it. This saw is probably a first generation also, doesn't have that new look. Just guessing but I imagine I could get this saw for cheap if I wanted it but I would pass if offered...