Stihl 026 non-start mystery

[Jeff Lary]

If your determined to use starting fluid go to Walmart and buy a $89.00 Poulan. Then give the Stihls to someone who will not ruin them. Take the starting fluid and shoot a hole in it with your largest rifle..., it is good for nothing else. You will ruin your engine eventually it washes all the oil present in the cylinder completely away. If you intend to continue to try to start the 026 get a compression gauge on it. I bet it is very low < 100psi. Good luck Jeff

 

[Totembear]

Well, either compression is low, its got a nasty air leak, or that spark is no good. Throw another coil on there. If I was you, I'd compression test it first, p&v test second, and replacement coil third. The previous two might save your arms a little fatigue.

 

[HarleyT]

The muffler on my saw has something of an outside "door", that can be removed with a couple of screws. Once that is off, I can see the (empty) interior of the muffler and the exhaust port. No noticeable buildup there, and I can see the piston moving up and down. There might be some scoring on the piston, but as mentioned above, I still get at least as much compression as I have in my 025. Interesting side note, when I added the couple of drops of oil to the cylinder, the compression went up dramatically for the first few pulls, much more than I would have expected.

Put up a pic. I am betting that it is a goner....

 

[merc_man]

Do you have a compression tester? Or going by feel.

Sent from my SM-J320W8 using Tapatalk

 

[merc_man]

Throw that starter fluid in the trash.
Get a spray bottle with mix instead.

You are causing more harm to the engine using that crap.

Sent from my SM-J320W8 using Tapatalk

 

[HarleyT]

It does cure gout!

 

[HarleyT]

Or was that WD-40?

 

[HarleyT]

Klotz oil will "rebuild" the damaged piston to "like new" condition!!

 

[Jeff Lary]

if you got oily hair it works wonders, just don't light a match...

 

[dmb2613]

I use it on gas fouled plugs works well

 

[HarleyT]

I use it on gas fouled plugs works well

A match? Or WD40?

 

[dmb2613]

A match? Or WD40?

Either then a match lol

 

[Wood Doctor]

The muffler on my saw has something of an outside "door", that can be removed with a couple of screws. Once that is off, I can see the (empty) interior of the muffler and the exhaust port. No noticeable buildup there, and I can see the piston moving up and down. There might be some scoring on the piston, but as mentioned above, I still get at least as much compression as I have in my 025. Interesting side note, when I added the couple of drops of oil to the cylinder, the compression went up dramatically for the first few pulls, much more than I would have expected.

You can take this saw to a local small-engine repair shop and they will likely have it running for about $100. At this point, I think that's a good option. Or, you can buy a new Stihl MS261 for about $600. Your choice.

 

[Belegedhel]

Well, thank you all for the advice and interest. It seems that the mystery is not so deep afterall. I borrowed a compression tester from the local auto parts store and put it on the 026 and it is only pushing 90 psi. Tried it on my 025 that runs like a top, and it only showed 120, so whether the gauge is imperically correct or not, it would appear that 90 vs 120 is the difference between running and not, and I need to calibrate my shoulder, as the pull on both saws felt the same to me. To corroborate that compression test, I pulled the muffler off of both my 025 and the 026. Upon closer inspection, it appears that the piston on the 026 is so scored that the piston ring no longer even stands proud of the ring groove (see pic). The piston on the 025 still had the original machining marks on it. So I would guess this saw needs a new cylinder and piston to bring it back to life, no quick and dirty fix here. No real surprise, as it was DOA when I acquired it, and I figured that if it was an easy fix, it wouldn't have come my way. Thanks again.

 

[merc_man]

You can get an after market P/C for cheap. You still got to find what caused the failure.

Sent from my SM-J320W8 using Tapatalk

 

[Jasonrkba]

It will run at 120. I doubt 90psi is enough to do anything. Judging by that picture it is beyond repair. Time for a new top end.

 

[Jeff Lary]

yea I think you found your issue.

 

[Whiskers]

That’s a lot more than a little scoring, no mystery there.

 

[president]

Probably just flooded real bad.
Take off the bar and chain for now.
Dump out all of the old fuel and pull the plug, and pull the rope a few dozen times and let the saw sit in the sun for a while.
Put in a new plug, and do not add fuel, but pull the rope a bit while holding the trigger down, see if it will hit.

After you are certain that it is totally dried out, then retry the squirt of fuel test. It should start and run until the squirt is burned off.

T1

 

[rupedoggy]

Look at that piston!