Husqvarna 435 Idle and Other Issues

[12151791]

Hey guys. First I wanna say thanks to everyone that chimed in on my sprocket question. I really appreciate it.

So the bar on my 435 is really worn, so I bought a new one today along with a new chain. I've been running standard high octane gas with husqvarna oil (50:1), but while I was at the store I decided to grab a can of premix fuel to run through it today.

I've been having the issue of the saw stalling on me for quite awhile now. If I throttle up it does just fine, but when I let off the gas it doesn't want to jump back into an idle, it just dies. I can start it up again and continue to use it no problem. When my cousin was here last week he suggested a new clutch (I didn't replace it when I replaced the clutch drum/drive sprocket) It wasn't really an issue until today, when I replaced the bar/chain and used different fuel.
Now it seems to bog down when I'm in the middle of a deep cut, and I'm not sure why. Any ideas would be appreciated, thanks.

 

[12151791]

Here's a pic of the spark plug if you need it

 

[12151791]

There's also an oily buildup around the muffler/spark arrestor screen

 

[bodyguy16]

I would start by replacing the sparkplug and cleaning the spark arrestor screen. It should help quite a bit, then you should possibly review your fuel mixture ratio accuracy looks oil heavy.

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[scottr]

There's also an oily buildup around the muffler/spark arrestor screen

What does the spark arrestor screen look like ?

 

[12151791]

What does the spark arrestor screen look like ?

 

[scottr]

Yep it needs cleaning . Have you ever ran your saw without the spark arrestor screen ?

 

[12151791]

Yep it needs cleaning . Have you ever ran your saw without the spark arrestor screen ?

I have not.

I cleaned it, switched back to my normal gas/oil mix and it seems to be getting better after it gets warmed up. Still dies after throttling like it always has though. It's weird, every now and then since I cleaned it, it sometimes runs at a higher RPM then it has in a long time. When it does that it has no problem cutting into deep logs.

I'm not sure if this is the case, but could running that high octane premix burn off buildup? I don't think I've had that oily residue pop up on the exhaust before like it has today.

 

[12151791]

I would start by replacing the sparkplug and cleaning the spark arrestor screen. It should help quite a bit, then you should possibly review your fuel mixture ratio accuracy looks oil heavy.

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I'll replace my spark plug tomorrow. As for the oil, I've just been using husqvarna oil (2.5gal) and mixing it with exactly 2.5 gallons of the highest octane, ethanol free gas I can find in the area.

 

[scottr]

I'll replace my spark plug tomorrow. As for the oil, I've just been using husqvarna oil (2.5gal) and mixing it with exactly 2.5 gallons of the highest octane, ethanol free gas I can find in the area.

 

[scottr]

Have you cleaned your air filter ?
It would be good to take the muffler off to look at the piston and cylinder .

 

[12151791]

Have you cleaned your air filter ?
It would be good to take the muffler off to look at the piston and cylinder .

I have not. It's only about 2-3 months old, but I've easily put a years worth of normal use on it since I bought it new. I'll do that stuff and post pictures of the piston/cylinder tomorrow when I have it off. Thanks for the help.

 

[backhoelover]

you either have trash in the carb. or have a air leak somewhere. need to pull carb and check and do a pressure and vac test. the 435 cylinder bolts are known for coming loose, i have seen this several times myself

 

[backhoelover]

check pm for service manual. also the c1t carbs are known for having problems

 

[12151791]

Just going to add some extra information here for fun/just in case. There seems to be some white smoke visible lately, not a whole bunch but enough to notice. Also it feels like it's consuming gas at faster rate than normal. While I was running it tonight after cleaning the spark arrestor screen, I noticed that it would go through periods where the upper level RPM's would increase to more acceptable levels, but it usually wouldn't last.

Thanks for the reply u/backhoelover. I don't have a lot of experience with tearing down carbs but I guess I can give it a shot if the little stuff doesn't help. Would the stuff you recommended fix the high end or low end? Or both?

 

[backhoelover]

Could be both carb teardown is in manual

 

[12151791]

Alright. So I cleaned the spark arrestor screen a little more thorough than I did yesterday. Took the muffler off and cleaned it up a little bit. I couldn't get a good photo of the cylinder, but I didn't see any scoring. Here's a picture of the piston. I cleaned the air cleaner up a little bit, it wasn't that bad. But in addition I threw a new spark plug in there and that seemed to help a whole bunch. Saw feels like it has some life back in it finally.

So what could be causing the spark plug (assuming that's what the problem was) to go bad so quickly?

 

[scottr]

Alright. So I cleaned the spark arrestor screen a little more thorough than I did yesterday. Took the muffler off and cleaned it up a little bit. I couldn't get a good photo of the cylinder, but I didn't see any scoring. Here's a picture of the piston. I cleaned the air cleaner up a little bit, it wasn't that bad. But in addition I threw a new spark plug in there and that seemed to help a whole bunch. Saw feels like it has some life back in it finally.

So what could be causing the spark plug (assuming that's what the problem was) to go bad so quickly?

I have never seen a Husqvarna spark plug but your picture looks like you are lucky it ran . To me the ground electrode looks like it is bent to almost touching the center electrode . Did you check the gap with a feeler gauge ?

 

[12151791]

I did. It was slightly under .020, which is the correct gap. It was a little tight but not terrible. The new one I put in was around .025

 

[bodyguy16]

I did. It was slightly under .020, which is the correct gap. It was a little tight but not terrible. The new one I put in was around .025

I was always told to start witht the simple things first, now that it runs better run her a bit to see it she still acts similarly under the said conditions and go from there.

I replace plugs every spring in all my equipement they're so inexpensive.



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