Stihl 026 not running

[Donald026]

Hello. So I have a Stihl 026 that wasn't running right and after my tinkering isn't running at all. And is now in pieces.

Little bit of info on my chainsaw experience. I have none. I am however mechanically inclined and I have taken an interest in this saw.

Here's what happened with the saw.

First of all. It was running, but wouldn't idle. Unless I had been on the throttle, it would die every time. Also, it was cutting really poorly.

Now, it did sit over the winter with fuel in it. And then I mixed up some new fuel for it. I mixed shell 93 v-power but I used some two stroke motor oil that has been opened and hanging around the cottage for who knows how long.

I started reading the manual and learned about the idle screws. I adjusted them a bit and it seemed to start to idle better but shortly thereafter stopped running altogether.

I've been researching vigorously for a week and I have been speaking with a couple guys at the Stihl dealership.

Here's my plan of attack for the saw.

1) Disassemble it for the most part and clean it really well.
2) replace the spark plug
3) rebuild and clean the carb
4) replace the fuel filter
5)inspect the fuel line, impulse line and Intake boot and replace if necessary
6) soak the air filter in soap and water and let dry
7) modify the muffler (4 hole type) open it up
8) mix brand new gas, with brand new oil
9) start up the saw and tune the carb.

Any thoughts?

 

[Dub11]

Welcome!

What carb does it have? Some of them came with a fixed High jet so if you do a muffler mod ot will be running lean.

Other than that it sounds like you are on the right track.

 

[Donald026]

It has the warlboro wt-194

It does have the three adjustment screws.

I've already purchased the carburetor rebuild kit from the stihl dealer but haven't gotten around to rebuilding it yet.

From all of my research I understand that these saws really suffer from air issues, and that's why opening up the muffler really seems to help. Can the air filter be modified to allow more air, or does the carburetor limit that anyways?

Aside from opening up the four holes into one larger hole on the muffler, is there anything else I can do to improve the performance of the saw?

I thought I might have a clogged spark arrestor screen, but upon taking the muffler off I see that it has been removed. There was, however lots of unspent fuel in the muffler which is why I decided to replace the spark plug and rebuild the carb.

The engine was completely flooded,

In reality. I think the real issue was with the fuel mixture. It was 25:1 as per the owners manual when not using stihl oil, but the oil was really really old.

Fresh fuel with fresh oil was probably the only thing the saw needed, but I really liked the idea of giving it a super good clean and tune up.

And then I started learning about the muffler mod. And now I can't stop thinking about working on this saw. I've been too busy lately, and now have the flu. But I'll be doing some work on it this weekend and posting some pictures and I'm sure I'll have questions.

 

[Dub11]

You have a good carb !

There is a metal mesh fainter filter that is available for them in Canada. I have one for my MOFO 026 and it has a deflector on the flywheel side of the muffler too.
And you can advance the timing of the saw to to help it out.

 

[Donald026]

I took this picture the other night after started to disassemble and clean the saw.

 

[Donald026]

I don't know much about advancing the timing. Does that involve shaving some material off the flywheel?

Also what does the deflector do?

 

[Dub11]

The deflector it covering the extra hole in the side of the muffler. Having the exhaust exhaust that way always it to breath but keep some of the noise down vs covering right out the front.

And on advancing the timing you you remove some material from the woodruff key to allow the flywheel to rotate counterclockwise. Usually
.020 is a good place to start.

 

[drf256]

Sure sounds like the choke flap in your air filter was stuck closed.

How does your piston look?

Check your saw for a vac leak as well. The flywheel side seal is usually the culprit.

 

[drf256]

I’ve seen seasoned saw mechanics go as far as a case split on a bad 026 when it was the airfilter. Even new OEM have been known to fail.

To the OP, the metal mesh OEM airfilter are available in Canada. They are called the “Winter Filter”. They cost me $40 US shipped, you can likely get for half of that.

 

[Donald026]

I was hoping to attract your attention. Al right?

I've learned a lot of what I've learned this last week from your posts.

Believe me. I am a complete rookie. I really don't know very much about small engines. So please try to be patient. Having said that I would definitely appreciate your help.

I did check the choke flap and it works very well. It springs back very well and doesn't stick at all. Looking into the cylinder from the muffler, there doesn't appear to be any scoring on either the cylinder wall or the piston, and when pulling the starter rope there seems to be good resistance.

How would I check for a vac leak?

Finally. The air filter I have I believe is a wire mesh but with fleece interwoven. I have half a mind to try to wire brush the fleece away as it is coming away in some spots anyhow and it seems many here prefer the wire mesh alone. Is this because there is less air resistance going in?

 

[huskyboy]

I was hoping to attract your attention. Al right?

I've learned a lot of what I've learned this last week from your posts.

Believe me. I am a complete rookie. I really don't know very much about small engines. So please try to be patient. Having said that I would definitely appreciate your help.

I did check the choke flap and it works very well. It springs back very well and doesn't stick at all. Looking into the cylinder from the muffler, there doesn't appear to be any scoring on either the cylinder wall or the piston, and when pulling the starter rope there seems to be good resistance.

How would I check for a vac leak?

Finally. The air filter I have I believe is a wire mesh but with fleece interwoven. I have half a mind to try to wire brush the fleece away as it is coming away in some spots anyhow and it seems many here prefer the wire mesh alone. Is this because there is less air resistance going in?

That’s a good way to ruin your saw if your using it for actual work. That mesh has bigger hole spacing than the real deal mesh filters.

 

[Canadian farm boy]

The air filter I have I believe is a wire mesh but with fleece interwoven. I have half a mind to try to wire brush the fleece away as it is coming away in some spots anyhow and it seems many here prefer the wire mesh alone. Is this because there is less air resistance going in?

This is the real deal metal mesh 026 air filter. PN is on the package.

Where are you located in Ontario?

 

[Dub11]

This is the real deal metal mesh 026 air filter. PN is on the package.

Where are you located in Ontario?View attachment 125353View attachment 125354

Lol I didn't notice the OP was in Canada with access to all the good stuff.

 

[Donald026]

That’s a good way to ruin your saw if your using it for actual work. That mesh has bigger hole spacing than the real deal mesh filters.

Thank you very much. I appreciate the heads up.

 

[Donald026]

This is the real deal metal mesh 026 air filter. PN is on the package.

Where are you located in Ontario?View attachment 125353View attachment 125354

I live just east of oshawa

 

[Donald026]

Why is the wire mesh filter the preferred choice?

 

[Canadian farm boy]

Why is the wire mesh filter the preferred choice?

They just breath better.
I notice improved throttle response and slightly higher wide open throttle rpms by just installing the metal mesh filter.
You may have to retune your saw slightly when going from the flocked filter to the wire mesh filter

 

[Canadian farm boy]

I live just east of oshawa

I'm located in Paris.

 

[Donald026]

Before and after muffler mod

 

[Donald026]

Before and after fuel filter and spark plug.


About to embark on the carburetor rebuild.