Husqvarna 141 Low Emission

[ChillyB]

Latest haul, a non-working 141. This is a low emission version. Guy bought for storm cleanup so used just a little while then stored for a long time. I’m guessing main issue is needing complete fuel rebuild.

What makes it a low emissions version, other than a green fuel cap? While I’m rebuilding the carb I’d like to undo whatever makes it earth-friendly. Something as simple as more restrictive limiter caps? Or are jets smaller?

One certain issue is the fuel line shows that it has been partially crimped shut by the carb adjustment boot.

 

[ChillyB]

Muffler is heavy. I see some manner of screen matrix inside so assume possibly a cat muffler.

 

[ChillyB]

Yep, it’s a cat muffler. The muffler has some really extensive shielding all around. I guess I’ll keep that shielding but get a regular muffler. Good protection for the tank in case of a leak.

 

[Woodslasher]

I'm guessing the Low Emissions means cat muff (Green cap on a Husky = Cat muff) and a "green" tank vent. I usually swap those out for an older style regular tank vent.

 

[ChillyB]

I'll have to research on tank vent. Didnt figure to take it apart that far (if it's where I think it is). Duck bill valve and bronze stone?

 

[Chevboy0167]

Tank vent should be same as standard emission I believe. Junk the cat muff for a $12 generic and open up the baffle holes inside, then open up the outlet just a bit.

There are a few different carb makes and models for these but most are Walbro. A LE version might have slightly restricted carb on it. I will advise to replace the entire fuel supply parts... filter in tank and fuel line. They get very brittle over time.

I can also guarantee the green impulse tube from the cylinder to that white plastic partition wall has a hole in it or at the very least leaks. Every saw of this series that I have worked on, that tube gets a hole rubbed in it from the rubber intake boot from vibration.

https://www.partstree.com/parts/husqvarna-530053435/

 

[ChillyB]

By "restricted" do you mean just smaller bore diameter? I can measure that vs carbs for 42cc Poulans.

 

[ChillyB]

"I can also guarantee the green impulse tube from the cylinder to that white plastic partition wall has a hole in it or at the very least leaks. Every saw of this series that I have worked on, that tube gets a hole rubbed in it from the rubber intake boot from vibration."

Terrific advice, and absolutely accurate.

 

[ChillyB]

An engineer needs a beat-down for crowding the pulse tube and intake boot like that. Failure seems inevitable. I wonder what a safe maintenance schedule would be for pulse tube replacement. Not a big deal if one knows to look for it. I sure do appreciate the solid advice on this matter.

 

[ChillyB]

Being the curious sort I filed off the edge of muffler crimp seam, peeled it like a spam can, cracker it open. Here's what a 141 catalytic converter looks like.

 

[ChillyB]

I drilled a couple holes on front cover, a couple more holes in the center baffle. I think I'll weld this back together and use it instead of a Chineeee eBay muffler.

 

[ChillyB]

Rebuilt the carb. Screen was sludged shut. A tiny bit of varnish. Once muffler is welded together and intake gasket and pulse tube arrives I'll be able to pull the rope. Compression tester shows 150 psi. No idea about case leaks, don't have the adapter made yet to connect my little hand pump. New fuel line is plumbed in. Eager to see the little bugger run.

 

[ChillyB]

Here is the extra heat shielding for the cat muffler. And it STILL scorched the top cover plastic out at the tip.

 

[scottr]

Being the curious sort I filed off the edge of muffler crimp seam, peeled it like a spam can, cracker it open. Here's what a 141 catalytic converter looks like.View attachment 984161

Is that a carboned up spark arrestor screen in the back of the muffler just inside the rear outlet ?

 

[ChillyB]

Yeah, it's a ridiculously small screen feeding a ridiculously small exit hole.

 

[scottr]

That outlet and small spark arrestor screen looks like a assembly that is welded to the muffler .
If I remember correctly that outlet is about 1/4" diameter which is about 0.049 square inch .
If you made that outlet 9/16" diameter which is about 0.248 square inch your saw will wake up without that cat .

 

[ChillyB]

Made my own impulse tube. Used a rubber cap for blocking off carburetor vacuum ports. Cut off the closed end, leaving just a smidge of the taper from the round end, then trimmed other end to length.

 

[Chevboy0167]

yep... ya got her wipped now! Fun little saws. Parts are cheap and plentiful.

 

[ChillyB]

Trimmed the swollen edges of the old intake gasket and installed with a bit of that white glue you fellas are so fond of. Then fired it up without a muffler.

For a little saw it takes a tug. Has 150 psi so couldn’t have been used too hard I suppose. Almost feels like timing is advanced the way it stops me cold mid pull. Like it kicks back or something.

 

[ChillyB]

Stuck the seams back together (won’t call it “welding” out of respect for those who do it for a living). Ready for final assembly.




Has a tin shroud all around the muffler, also a tin shield that was plastic-riveted to the underside of the lid. Plastic nubs were burned away except for one so put in some aluminum rivets.

If a moderator moves this to the “hot saw” forum I’ll understand.