My Stihl 026 blew the piston

Backcountry · October 07, 2015, 09:34:16 PM

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 · October 07, 2015, 09:48:11 PM

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 · October 07, 2015, 10:11:49 PM

Quote from: Maine372 on October 07, 2015, 09:48:11 PM
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 · October 07, 2015, 10:46:06 PM

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 · October 08, 2015, 07:37:30 AM

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 · October 08, 2015, 08:48:41 AM

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 · October 08, 2015, 10:51:44 AM

Quote from: bandmiller2 on October 08, 2015, 08:48:41 AM
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 · October 08, 2015, 11:03:34 AM

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 · October 08, 2015, 04:07:11 PM

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 · October 08, 2015, 05:26:19 PM

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 · October 08, 2015, 06:17:46 PM

Was the 026 known for crank seal problems?

ladylake · October 08, 2015, 06:42:32 PM

Yes. Steve

nitehawk55 · October 08, 2015, 07:49:55 PM

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 · October 08, 2015, 09:27:22 PM

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 · October 08, 2015, 10:56:55 PM

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 · October 09, 2015, 06:39:00 AM

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

teakwood · October 09, 2015, 09:08:57 AM

Quote from: Mopar70 on October 08, 2015, 06:17:46 PM
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 · October 09, 2015, 09:13:16 AM

Yes

Quote from: ladylake on October 09, 2015, 06:39:00 AM
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 · October 09, 2015, 01:01:11 PM

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 · October 09, 2015, 05:04:38 PM

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 · October 09, 2015, 05:30:59 PM

I can agree with

Quote from: teakwood on October 09, 2015, 05:04:38 PM
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 · October 09, 2015, 05:58:26 PM

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 · October 09, 2015, 10:00:28 PM

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 · October 09, 2015, 10:14:54 PM

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 · October 09, 2015, 11:49:08 PM

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.