Husqvarna 353 - at a loss here, need help

[MartDalb]

Hey everyone

Rarely do I have to completely put down a saw and give up.

So long story short.

Used husqvarna 353, bought cheap, no history on it, only that it would not run.

I do the usual tricks.
Check fuel lines
Clean carb and replace diaphram etc.
Check impulse line
Check piston looks clean
Check muffler and spark arrestor.
Rechecked with 2 other spark plugs.

Also replaced the oil line because she was spilling.

Thinking it would start right up, not so.

It pops on choke, and then sounds awful on idle it hardly idles, sputs and can not rev at all, dies out with a loud pooof.
Rechecked everything. Same problem again.

Popped off the manifold and found the clamp heated and melted around the rubber manifold. Not sure if this is the issue, my bet would be it is not.
I Will have to replace both manifold and clamp part though.


But... What the hell is the issue here?
Faulty carburator?
Faulty ignition coil? It has spark but...

I can't seem to come up with any other possibilites.

Pictures attached.

All help and ideas are most welcome!

 

[Cantdog]

Odd to see the rubber intake melted......That will need to be replaced as it's certainly a good chance for an air leak and I would toss that Husky clamp and get a Stihl clamp....034-036...tightens up with a screwdriver. Much better clamp. Piston looks real good. Still has machine marks both sides so not a tremendous amount of hours.

 

[Wood Doctor]

I might add that it never ceases to amaze me how many Stihl models use the same size pipe clamp to hold the intake manifold boot to the cylinder.

 

[MartDalb]

Odd to see the rubber intake melted......That will need to be replaced as it's certainly a good chance for an air leak and I would toss that Husky clamp and get a Stihl clamp....034-036...tightens up with a screwdriver. Much better clamp. Piston looks real good. Still has machine marks both sides so not a tremendous amount of hours.

I agree.
The manifold is done for as well, rubber melted stuck to the clamp, no obvious hole into it though, not sure if this is the main cause of the saw not running correctly.
I mean, it pops, but the sound it made/makes when trying to idle, and then no responce when throttle.
Dieing with a loud pooof and some smoke from the muffler.

Weird...very weird, never heard a saw do that, ever.
It doesn't rev, doesn't high idle, it just...sounds like something is really stuck, and dies out after 10seconds or so. This is why I took off the cylinder, but no real issue inside either...

 

[Wood Doctor]

Looks like there may have been a long-term heat buildup as the intake manifold gave up slowly until nothing was left. Then the air leak was so large that the engine just plain could not run (Air/Fuel ratio way too high). Original owner could have given up on it several years ago.

This is my go-to saw for most firewood collecting. It replaced my 026 PRO that I still use occasionally. Husqvarnas tend to grow on you, especially this model. So, it's worth fixing. Original cost was about $400 nearly 11 years ago.

 

[MartDalb]

Looks like there may have been a long-term heat buildup as the intake manifold gave up slowly until nothing was left. Then the air leak was so large that the engine just plain could not run (Air/Fuel ratio way too high). Original owner could have given up on it several years ago.

This is my go-to saw for most firewood collecting. It replaced my 026 PRO that I still use occasionally. Husqvarnas tend to grow on you, especially this model. So, it's worth fixing. Original cost was about $400 nearly 11 years ago.

Thanks for the reply Edwin, much appriciated as always!
Yeah I want to get this one up and running, it has not seen much work, but the work it has seen seemed to have done something funky to it.

I tried could seperating the manifold and the clamp plastic part, simply would not go, ended up ripping the rubber, as it was stuck together completely.

Do I then assume that this caused an air leak, making the saw run this oddly?

Would the piston etc. not show sign of wear?
I am really worried it might be a defective carb or ignition coil (though I have rarely seen defective coils).
But on the other hand, this burned "plastic clamp" and manifold is the only part I can visually find that is faulty. How they burned it, I have no idea.
(edit) Will also add, the clamp and manifold WAS sitting relatively tight around the cylinder port hole....but I can't varify if there was a massive air leak, obviously.

 

[MartDalb]

I'd post more pictures, but nothing to conclude from it, other than it's a very pretty saw, and it hasn't been used a lot.

 

[Wood Doctor]

Here's mine, about 11 years old, and its been used a lot:

Still has good compression and power. I bought a used non-running 350 for back up and got that one running again. It had a broken manifold clamp that I fixed.

 

[MartDalb]

Here's mine, about 11 years old, and its been used a lot:
View attachment 1002269
Still has good compression and power. I bought a used non-running 350 for back up and got that one running again. It had a broken manifold clamp that I fixed.

That is a lovely saw! Nice job.
For the record, I am not a fan of those clamps that aren't screwed on tight.

Which would be the one to use instead of the standard version? Part nr. 588 77 55-02?, I used that on the Jonsered 2159 we just finished a few weeks ago, with your help

 

[9050LX]

Is the impulse nipple open?Looks like an easy manifold replacement.

 

[MartDalb]

Is the impulse nipple open?Looks like an easy manifold replacement.

impulse hose is fine, good condition, but as mentioned manifold, clamp part is broken.

 

[Wood Doctor]

The only part my IPL shows is 503 86 62-01. You may also need 503 86 63-01 and/or 503 86 64-01 if they are damaged from heat. But, I doubt the latter got that hot.

 

[MartDalb]

Is the impulse nipple open?Looks like an easy manifold replacement.

You would shoot for this sort of behavior just from an air leak in manifold?
I guess it is a first shot at it, seeing as both you and others are already thinking this.

 

[MartDalb]

The only part my IPL shows is 503 86 62-01. You may also need 503 86 63-01 and/or 503 86 64-01 if they are damaged from heat. But, I doubt the latter got that hot.

hmm, this has me thinking.

I don't have that last part on mine, 503 86 64-01.
See my pictures.
Mine is a trio brake version btw. (not a fan, I might just take that brake off)

 

[Wood Doctor]

That impulse nipple on the boot could get clogged up with that much burn up. Worth checking, but I think you are OK there.

 

[MartDalb]

View attachment 1002280
That impulse nipple on the boot could get clogged up with that much burn up. Worth checking, but I think you are OK there.

Yeah, blew some air through, was fine airflow. Mine is not build up like this, that 503 86 64-01 isn't present on what I have.
Mine has a 544 45 29-01 part instead.

 

[MartDalb]

If, the manifold and clamp is not the issue.
What would be the next thing to search? I have felt air leaks before, but nothing like this.
The saw not wanting to even feel my throttle, the loud poof sound when it dies... I'm not convinced this is the main issue honestly.

 

[9050LX]

Air leaks run hot.I had a 350 that melted the nipple closed.My piston didn't look as good as yours. You could replace the manifold,button it up, then test for your air leak.

 

[J D]

Timing might be out, probably worth checking coil, gap, flywheel etc

 

[rupedoggy]

Timing might be out, probably worth checking coil, gap, flywheel etc

+1