My Stihl 026 blew the piston

[Backcountry]

Hey Folks,

I'm most appreciative of this forum, it's been a great source of info to help me keep the old chainsaw running.

I purchased a rebuilt 026 a few years back. It ran fairly well, my first saw, so I'm pretty green. I always had trouble keeping the idle running properly and I'm guilty of using old gas (although I do mix with stihl oil as I go). This past winter I rebuilt the carb hoping that would help with my issues. Also replaced the plug, fuel filter and cleaned the air filter. I was able to get it running a little better than before, but continued to have trouble with the idle. Finally it just kacked outright and I couldn't get it back up and running. Took it into a Stihl dealer and they told me the piston is cracked and scored. They have no interest in rebuilding it, as it wouldn't be cost effective for either of us.

Think it's worth my while to try and find someone to rebuild it, learn myself, or just bite the bullet and get a new one? I don't really have budget for that, but it's making wood season... I guess if I was have to it rebuilt, then the question begs, why did it overheat or fail. It's entirely possible that the saw was in retirement mode when I bought it, I understand it's a PRO model, and may have been worked pretty hard. Tough to say...

Appreciate the feedback.

Thanks.

[Maine372]

026 is a great saw. on par with a 346 in my opinion. so yeah its probly worth fixing.

its not just a simple matter of putting on new parts. you need to figure out what caused the failure. if your idle was giving you fits I suspect it was pulling air in somewhere and not getting enough fuel to stay running.

that being said it sounds like your in a position to fish or cut bait. if its wood cutting time bite the bullet, get a saw to get the job done. then fix the 026 to have a back up machine.

[Backcountry]

it sounds like your in a position to fish or cut bait

:D

All good advice. It makes sense having a backup machine. From what I've been able to glean, the 026 is a great machine so it would be great to keep running, especially if can keep the repair cost down. It's already been a helpful learning experience rebuilding the carb, so even if I don't get it working again, I can at least gain something by tearing it down I rekon.

It seems to me when it was failing, the symptoms seemed to be at least somewhat indicative of bad rings. Could that have caused said air leak?

[sawguy21]

Bad rings will cause loss of compression and power but not an air leak. He is talking about a bad gasket or crankshaft seal. Two stroke engines need to be air tight downstream of the carburetor to work properly.
Pictures of the damaged parts would help us immensely to help diagnose the cause. An 026 is worth rebuilding the top end but first you need to determine the problem to keep it from repeating.

[thecfarm]

Backcountry,welcome to the forum. I had trouble with my Husky with air leaks. Would run fine at cetain postions at times,and other times it did not matter. I could tell it was not right. I don't work on my saws so I had to pay to have it done. Once the piston had to be pulled,that was a bill to pay. Than another time was just a little rubber line.
Your saw may need to be tested for air leaks. But I have no idea for sure. Others know way more than I do.

[bandmiller2]

Backcountry you might as well jump right in the swamp with both feet and learn how to repair your saw. Theirs plenty of help here. Some won't agree but after market parts make it practical to repair an older saw. The advice about a new saw is good too a fella should have at least two saws. Frank C.

[Backcountry]

a fella should have at least two saws

Yeah I like the sounds that... Someone once gave me an even older 030 AV. Maybe I can get that old girl up and running in the mean time.

[LeeB]

If you can rebuild the carb, you can redo the top end. It's not that hard. I was scared of it but got through just time with my Husky 346. Wouldn't hesitate to tackle another one now. I'd be more scared of the carb. (haven't done one yet)

[Backcountry]

It seems like a common enough saw, so hopefully I can round up enough photos and videos to give it a go. I guess the trick might be finding the new parts.

How much $$ is too much to fix it?  I noticed on another thread something was looking at buying a rebuilt 026 for $175. When I got it about 5 years ago I paid $350.

[ladylake]

 

I think you can get some reasonable aftermarket cylinder kits for that saw, don't buy the cheapest one , I think Meteor makes a good one ..  Replace the crank seals for sure, plus the fuel line and a carb kit.  If it doesn't run right DONT run it, figure out why.   Steve

[Mopar70]

Was the 026 known for crank seal problems?

[ladylake]

 Yes.  Steve

[nitehawk55]

I've had great luck with the Hyway kits but I get Caber rings too , I don't like the dark cast rings that come with those kits . You can get them from HL Supply along with other parts .

[Backcountry]

Interesting, HL Supply has a great selection of parts! I see you are in Ontario, so cross border shipping must not be too bad.

Looks like something like this would be the ticket:

http://www.hlsproparts.com/Stihl-026-MS260-big-bore-nikasil-cylinder-kit-p/h30026-b.htm

This gasket set includes a crankcase gasket, is that the crank seal?

http://www.hlsproparts.com/Stihl-024-MS240-026-MS260-gasket-set-p/h40260.htm

[dougand3]

The crankcase gasket is the long, funny shaped one - after you split the case. The crank seals are the round rubber and metal ones - the flywheel and clutch sides of the crankshaft poke thru them.

[ladylake]

 I don't think you have to split the case to get new crank seals in??    Steve

[teakwood]

Was the 026 known for crank seal problems?

No. I have had 5 MS 260 over the last 12years. Thats the only saw we us in my teakplantations. Light and powerful pro saw. Never had a problem with them. The newest is 2 years old and i still have 2 left who are 10 years old, the rest is disarmed and used for spareparts

[dougand3]

Yes

I don't think you have to split the case to get new crank seals in??    Steve

Yes, I didn't word that well. Need crankcase gasket IF you split case. You should be able pull the seals out with a dull screw.

[Backcountry]

Came across this rebuild kit on ebay. Includes everything I may need and then some at a nice price.

Offsite photo and Ebay ad deleted by ADMIN.

Just asking for trouble with this unbranded stuff?

[teakwood]

I would not buy such kits. I mean its a pro saw not a homeowner saw. every thing on this saw is made with such high quality and standards to hold up daily heavy duty use and abuse.
although i can not tell from experience if this kit will work or not. i always buy original parts

[Mopar70]

I can agree with

I would not buy such kits. I mean its a pro saw not a homeowner saw. every thing on this saw is made with such high quality and standards to hold up daily heavy duty use and abuse.
although i can not tell from experience if this kit will work or not. i always buy original parts

I can agree with this, your not shure what you are going to get.
have you looked into any reviews on this?
but on the same note, what do you have to loose?
I would be conscerned on how long it took for these parts to come in.
installing the top end with new gaskets and all the plumbing shouldn't be much of a challenge.
If you plan to run your 026 daily for any extended amount of time i would consider somthing different.

[Backcountry]

Yeah I totally hear ya on good parts. My laptop is my daily tool and I make sure to use top end parts.

As far as the saw parts go, if it's a case of the same factory making the same parts as branded then that's one thing, but sounds like there could be a pretty big discrepancy in quality. If I'm going to end up having to buy the same parts again because they aren't quite right, then I may as well spend twice as much, once.

The saw for me doesn't see daily use at all. Need it for occasional storm clearing, a couple cords of wood a year and random odds and ends.

[dougand3]

I've used similar top ends for 5 Husky 55 saws. Have bought from the same company. I found the castings to be good quality, although needed a minor adjustment of enlarging impulse hole to talk with crankcase = no biggie. For what you describe usage-wise, I bet it would be fine. Shipping to USA takes 10-14 days.

[Texas-Jim]

Its very possible the cylinder is fine, if so then perhaps just a piston and rings. I usually dont do just a piston but if money is concern it may be prudent. The piston #1121 030 2001 is only 35 bucks or so and thats a Stihl part. Might be worth pulling it apart to check on condition of the cylinder.

[Backcountry]

Yeah, I've been putting the cart ahead of the horse. Gotta get the saw back from the shop. Then I'll tear it down and should get a better idea of what actually needs to be replaced. As well as hopefully the marks on the piston will give more clues as to what caused the failure. Then I can also make some assumptions on additional parts I should order.

[LeeB]

If you go to the trouble of tearing it down, replace the rubber goods, fuel line, impulse line, and vent line. Cheap insurance and likely will solve whatever happened before.

[Al_Smith]

If that thing actually has a cracked piston chances are it ingested something it should not have .Stihl cylinders are pretty tough also a good chance the cylinder might be okay .


A good after market piston/rings  such as a Meteor will be around 30 dollars .Seals maybe 20 OEM ,half that after market .So for maybe 50 and change that might cure it .

Contrary to what some might think it doesn't have to be factory fresh to run well and run good for a long time.If a dealer did the work you will have more in it than the saw cost new .

[Magicman]

I see where FF Sponsor CHAINSAWR (Scott) has a 026 piston listed for $25.49. LINK  about 2/3 down the page.  I would give him a call.

[Al_Smith]

Hey hey hey,I'll put in a plug  for Scott .One of the best parts suppliers on the internet .

[Backcountry]

Thanks for all the tips folks, much appreciated!

There was a time a couple years back, where I was cutting a lot of maple and the saw died on me, I saw lots of white smoke coming out of it. It was never right after that, seemed low on power, although it worked better than recent days. Maybe that was the original fault, and I was just limping it along since then, doing more damage.

If that thing actually has a cracked piston chances are it ingested something it should not have

I know that feeling... Like something in the gas or air that slipped past the filter?

Hope to get this back soon, and I'll post some photos of the piston/cylinder.

In the meantime, back to cutting 4" Oak with my 18v Sawzall  :D

[dougand3]

Ingesting into engine thru fuel line is unlikely. Screen in carb would catch it. Sneaking around air filter is more likely. Or if the piston cracked first, a piece of it bounced around the crankshaft and may have worked it's way upwards, past the ring,  to the top of piston. That gets ugly.

[dougand3]

Here's some bad indigestion for you. PP260 - the choke rod broke, screw holding the plate freed up and shot into intake. Either Walbro made a cheap rod or buyer was too rough yanking choke too hard.

[Al_Smith]

In my shed resides an early Stihl 038 magnum that spent over 20 hard years in tree service work .That saw ingested something that literally grenaded the piston .

It didn't as much as even put a scratch on the cylinder .Mahl made some tough plating .New OEM piston and it probably runs and cuts as well today as when new .

[Weekend_Sawyer]

Id like to have a peek in your shed Al!

[WV Mountaineer]

First off.  Rebuild it!!!!!!!  Great little saws

My first choice would be chainsawr kits or a used part.  I bought a rebuild kit from him for my 385 and it was wonderful.  If he doesn't have one, I'd stick with the Hyway or Meteor kit.  Although, my uncle rebuilds and runs hutzul and loves them.  Only thing I'd do is buy some caber rings and use them instead of the provided ones in whatever kit you choose.

Check the crank.  Replace the crank bearings while you are at it.  I'd really replace all rubber lines and rubber intake boot.  Might as well replace the fuel filter too.  You could rebuild this saw for $130 if you replace everything.

Whatever you do, save the saw instead of junking it.  Even if you have to put it aside for now.  It is an easy fix.  God Bless

[Al_Smith]

In addition to all the other advice something to think about .In my own little world I've found out given enough time concerning chainsaws that eventually when you least expect it a donor saw will pop up .

It could be something a simple as somebody backed over it with a lawnmower and broke the handle .Fact I've got a dandy of a Stihl bg 85 blower that lost a battle with a dump trunk . Freebie,the donor was 57 bucks including shipping fleabay .You just never know .

[Backcountry]

Thanks WV good tips!

In my own little world I've found out given enough time concerning chainsaws that eventually when you least expect it a donor saw will pop up .

True enough, the universe provides... I was given a much older looking Stihl 030 AV. Not sure how far it's from running, but I'm sure I'll learn a thing or two from the 026, and move on down the bench and maybe get that one running as a spare, or to pass on to someone else who is in need. No chain brake though, and manual oiler 

[Backcountry]

<sigh> $65+ tax to find out the saw is a 'write off'. And they gave it back with the muffler detached missing the bolts. I'll be lucky if other parts aren't missing too.  >:(

Well, time to dig in...

[Weekend_Sawyer]

why is it a write off? cylander scored? I'm curious.

[ZeroJunk]

<sigh> $65+ tax to find out the saw is a 'write off'. And they gave it back with the muffler detached missing the bolts. I'll be lucky if other parts aren't missing too.  >:(

Well, time to dig in...

I doubt they did anything other than take the muffler off.  5 Minutes maybe. 

$65 is insane. Stihl store here charges $25 which I can understand. And, what is the tax on ? Labor ?

[Backcountry]

I doubt they did anything other than take the muffler off.  5 Minutes maybe. 

My guess as well... I asked the guy if it was the just the piston or also cylinder, he said both were scored. I asked if I needed a whole new top end, as I was going to rebuild it, and he said yes. I probably could have asked if my hair was on fire and he would have said yes... He wasn't the guy who actually looked at it.

It's a write off, because they sell new saws instead of rebuilding old ones.  :-\ I thought I'd found the right shop, but clearly not.

[isawlogs]

Tax must be on service......  Get them to give you new screws for the muffler, they should of been there when you got your saw back.

[Al_Smith]

More times than not shops will knock off the service fees if the person buys a new saw. For a picker like myself I buy them at 50 a pop for a complete saw that more times than not needs very little work .

[Backcountry]

I went back for the screws. "oh he wants them?"... They gave me 2, but from what I recall I need more than that, some for the inside and outside. Just wanted to get the eff outta there, I'll figure it out.

And yeah, if I wanted to buy a new saw, theoretically I'd get my $65 back on the price.

[Al_Smith]

If all they did was look at the piston through the exhaust port there might not be anything wrong with it .Maybe some burn might be all .

The last saw I got out of a dealers dead pile was an 024 Stihl, complete including a plastic bar guard.50 bucks .Slight piston  burn not bad .All I did was cut the baffles out of the muffler and retune it .Neat little saw.

More than likely the owner was told the saw was beyond repair and he bought a new one .So there you go .

[Backcountry]

ARgh... Going to have to get a longer torx bit to get at the last two bolts on the cylinder. Looking through the exhaust port it seems like the piston has some breakage. I can't get a good photo of the cylinder wall, but it looks like it could be scored.

[ZeroJunk]

Good lord, I don't believe even JB weld will fix that.

[Backcountry]

Good lord, I don't believe even JB weld will fix that.

:D

[fossil]

I would say you are definitely looking at a piston and cylinder. More to think about is where that missing piece of piston has gone. You are going to have to make sure it's not in the crank case and if it is, that it hasn't damaged your crankshaft bearings. Sometimes they end up going up the transfers and into the cylinder.

You will definitely need to look for the cause of the damage. If it wasn't straight gassed or accidentally run too lean there will be an air leak somewhere.

[sawguy21]

YIKES!!! That is one of the worst I have seen. It is more than straight gassed, I wonder if it ingested the rod bearing which means a complete tear down. Probably not worth fixing if you have to buy a new crank.
Many shops have a minimum 1/2 hour flat rate charge but $65 is excessive, that is probably an hour for writing up a service order, removing the muffler and turning on a penlight.They apparently would rather sell than service which IMHO is foolish, there is far more money in parts and labor.

[Backcountry]

$65 is excessive, that is probably an hour for writing up a service order, removing the muffler and turning on a penlight.

That's exactly it. Plus they were two weeks doing all that, so I guess there is some rent, insurance, and storage built into that as well... 

It was never straight gassed while I had it, although I am guilty of using old gas. Although, somewhere along the line I became under the impression that the mix ratio is 50:1, but I'm reading elsewhere that people normally go 40:1 or even 35 on a rebuild. Not straight gas, but maybe not enough lubrication, especially if it's old gas. Hopefully once I'm able to dig in deeper, all will be revealed. In the meantime I have an opportunity to bid on a new stihl saw at an under attended silent auction. That may be my best bet for the short term.

[Al_Smith]

Oops! That one evidently ate something that didn't agree with it .Have a eulogy and bury it on the shelf as it might have some usable parts for another project .---things happen ----

[fossil]

If you wait until the Fall is over and the sell prices drop, you should be able to pick up a good used 026 or 034 for around $250 which may be your best bet if you don't want to spring for a new MS261 which are generally $700.

[nuke1]

we recently rebuilt 026s from ebay $50.00 kits firts one had good rings but the ladt one had the cast rings and so replaced them with a stihl set , but with good high idle break in . They both run well and are back up saws for a tree service that has a dozen of them