Husqvarna 128LD Will Not Stay Running

[PTmowerMech]

So let me update you all. Forget everything I posted above.

This weed eater is starting just fine. Idling OK. and when given gas it slowly (slower than I think it should) revs up. It hits a certain audible RPM sound and then bogs out and dies. There is no saving it when it does this. You cannot pump the throttle, you cannot take your finger off the throttle. It just simply dies. It did this with both the old and the new carburetor. Exact same RPM, exact same timing, everything.

What I have done to it.

1. Brand new OEM carb. Misbehaved the EXACT same way as the aftermarket carb on previously before.
2. Muffler has been totally cleaned as well as spark arrestor that has been completely removed (worked the same as before it was off, same as after it was clean, same as after I completely removed it).
3. Brand new fuel lines.
4. Brand new fuel filter.
5. 102 PSI of compression.
6. Fresh ethanol free gasoline with a 40:1 mixture. I'd rather run it a little richer than to lean (I believe it calls for 50:1)

I checked the cylinder the best I could while the muffler was off. It looked good.

I am not a small engine mechanic. Obviously. I pretend to be one. I have never ran into an issue I couldn't at least diagnose what the problem likely is. This is getting beyond frustrating and at the same time, killing my pride of being a pretty dang good handyman.

I will look into getting the tool to adjust the carburetor. Again I am not a small engine mechanic, but I just feel like this is not the solution, but am totally open to trying it.

Thanks to everyone who has replied so far.

EDIT: I ordered a carb adjustment and cleaning tool kit on amazon. It came with like 8 different carb adjustment tools and some cleaning rods and brushes for like $12. Has the husky tool in the set.

Start it up and let it idle for a few seconds. With one hand on the throttle, and another on the choke, as you squeeze the throttle til it starts to die, rock the choke on and off pretty fast.

If it's doing the same exact thing on two different carbs, than I understand what you're saying about it not being a carb problem. But bogging down, when you squeeze the throttle is a carb or compression problem.
If you have good eyes and a very small high beam flashlight, you can also look down in the cylinder through the spark plug hole and sometimes see a lot more of the cylinder.
I'm not sure what type of compression tester you used, but as @bertsmobile1 has pointed out to me a few times now, compression testers are no accurate. But they do give you some idea as to whether its got compression or not.

But try the choke trick and report back. Everything you're saying makes me think it's a carb problem. Except for having different carbs on it, and it still doing to the same thing.

BTW, When you do throttle it up, does the head turn at all? Just thinking something could be bogging the engine down.

 

[AVB]

5. 102 PSI of compression.
Failure of test. Stuck Ring or PNC Damage

 

[DerekF]

Some remote thought. If this had the newer style variable ignition timing module with the built in rev limiter you could have a faulty ignition module also that could cause weird symptoms. Nothing like fighting a faulty module that never looses fire,but in your cause you could be loosing fire above a certain rpm.

I was wondering this at one point, I am going to look into it as a possibility. This machine is just so basic that I would be surprised if it has than, but I appreciate the comment. Ill let you know what I find.

Start it up and let it idle for a few seconds. With one hand on the throttle, and another on the choke, as you squeeze the throttle til it starts to die, rock the choke on and off pretty fast.

If it's doing the same exact thing on two different carbs, than I understand what you're saying about it not being a carb problem. But bogging down, when you squeeze the throttle is a carb or compression problem.
If you have good eyes and a very small high beam flashlight, you can also look down in the cylinder through the spark plug hole and sometimes see a lot more of the cylinder.
I'm not sure what type of compression tester you used, but as @bertsmobile1 has pointed out to me a few times now, compression testers are no accurate. But they do give you some idea as to whether its got compression or not.

But try the choke trick and report back. Everything you're saying makes me think it's a carb problem. Except for having different carbs on it, and it still doing to the same thing.

BTW, When you do throttle it up, does the head turn at all? Just thinking something could be bogging the engine down.

Today I tried your choke trick, when this engine bogs out and dies, it very quickly bogs out and dies, there isn't much time to try and stop it and I haven't successfully manipulated it to stay running. It immediately dies every time.
As for the head turning, no. It like intermittently starts and stops, not necessarily with how fast the engine is cranking. I should have thought to mention this before. I took the whole shaft assembly off the motor end of the trimmer and spun it with my finger. It spun very freely. If this is related, its got to be up in the clutch area I am thinking? The trimmer head behaves some what oddly when giving it more gas.

5. 102 PSI of compression.
Failure of test. Stuck Ring or PNC Damage

What is PNC damage? What would indicate a stuck ring as far as sound or bahavior?

 

[Darryl G]

Are you still running it with no fuel filter? You need to make sure the fuel line is submerged in gasoline at all times and the filter weights it down.

 

[DerekF]

Are you still running it with no fuel filter? You need to make sure the fuel line is submerged in gasoline at all times and the filter weights it down.

In my update I wrote that I had a new fuel filter on it. Its submerged. Still not running right. Its my dads weed eater and I have been making lots of extra little cash fixing broken small power equipment and selling it. Since I have had so much success I am considering trying to do a little small engine repair on the side, so this was extra practice before putting myself out there like that. He didn't have a fuel filter on it, I was trying to get it going without spending any money since its not a paid job, and i'd just put one on after I got it working, since you suggested putting one on it, I decided I would. So there is one on it now. This is a humbling experience to help me realize I probably have a ways to go before advertising as a small engine mechanic.

 

[Darryl G]

In my update I wrote that I had a new fuel filter on it. Its submerged. Still not running right. Its my dads weed eater and I have been making lots of extra little cash fixing broken small power equipment and selling it. Since I have had so much success I am considering trying to do a little small engine repair on the side, so this was extra practice before putting myself out there like that. He didn't have a fuel filter on it, I was trying to get it going without spending any money since its not a paid job, and i'd just put one on after I got it working, since you suggested putting one on it, I decided I would. So there is one on it now. This is a humbling experience to help me realize I probably have a ways to go before advertising as a small engine mechanic.

Ok, sorry missed that.

I run Husqvarna trimmers for my lawn care business. I had one of those trimmers and it's a low-end model that don't tend to be very long-lived. They're kind of heavy and clumsy for the power they provide as well. I gave mine to my son for the small lawn at his apartment and wont miss it. The 223, 323 and 326 are much better units. I'm running a 525 most of the time now but still like the light weight of my 323.

I think that unit has already been more trouble for you than it's worth honestly.

 

[PTmowerMech]

In my update I wrote that I had a new fuel filter on it. Its submerged. Still not running right. Its my dads weed eater and I have been making lots of extra little cash fixing broken small power equipment and selling it. Since I have had so much success I am considering trying to do a little small engine repair on the side, so this was extra practice before putting myself out there like that. He didn't have a fuel filter on it, I was trying to get it going without spending any money since its not a paid job, and i'd just put one on after I got it working, since you suggested putting one on it, I decided I would. So there is one on it now. This is a humbling experience to help me realize I probably have a ways to go before advertising as a small engine mechanic.

I know what you mean. That's how I started out a few years ago. And still starting out. Getting hung on one trimmer you can't figure out, is nerve wracking. To say the least.
This is a little off topic, but I got a throw away brand running once. As far as my compression tester could tell, it had over 100lb. And after getting it running good, I sold it to someone who brought it back the next day. I cleaned out the carb, tuned it up and it was running great again. So the customer came back and got it. Called me the next day with the same problem. So I just gave her her money back.
Repeated the same process again, and I still have it. It still runs good.

But back to your problem. I'm at a loss.

Does it idle ok? Can you crank it up and just let it sit there and idle for long periods?

 

[JBtoro]

Before you start adjusting it with your new tool, turn each carb's screws in (clockwise) until they seat & count the revolutions. Put a paint mark or something on the handle so you can have a reference. Should be 1 1/2 to 2 turns. If not, maybe that's the problem; ie, they were set wrong or perhaps too lean at the factory. Then, as AVB advise, turn them back out 1 1/2 turns, start it up & try tuning the carb with your tool. If it still fails, you might want to try 2 turns out for starters since your issue is that it bogs when you give it more throttle. Wish I could give you more, but often it is just requires a lot of patience, trial & error, & a good ear.

 

[DerekF]

Thanks everyone for all your comments and time. It's been a frustrating little job and I never figured it out. I did the screw adjustments on the carb, screwed all the way in, then backed out 1.5 turns and tried to tune it it from there. It never changed anything. I appreciate everyones thoughts.

Question for those small engine mechanics out there. If you run into issues like this, where you just can't figure it out (if that ever happens to you), what do you tell your customer? Also, at what point do you tell your customer that the machine just isn't worth fixing?

 

[Rivets]

Just read through the entire thread and I’m wondering if you checked the crankshaft seals? If one of the seals has a slight crack, it will allow air into the crankcase, creating a lean mixture.