Stihl 026 refresh ?

[bowtieman427]

14 yr old son and I cut firewood for our home. His goto saw is a Stihl 026 which use to run very well. latley it has been having issue to continue running. We tweaked on the carb and needless to say it got worse. I will start but will NOT idle at all if WOT it will go to about 8000RPM then quits. Cleaned carb reinstalled and no change. Blocked off the I and E. applied vacuum and pressure to the impulse line and it was 0. Figure it is time to give the saw a good going over refresh install new crank seals, fuel, impulse line, maybe new intake boot. Basically taking it all apart for a good cleaning and freshen it up. Presently looking through the I & E piston and rings looks pretty good do not have a compression gauge that will work on the saw but visually look nice. Son wants to take the head off and port and polish as well as modify the muffler 1 hole to 3 or 4. Wants to make it run a lot better.
1) If we take the head off if we see any damage and must get piston or rings do we rehone the cylinder ?
NOT sure if the 026 is chrome, or NIK-SIL. or how to tell. I assume Nik-Sil would see honing marks but not to sure with chrome or if just AL. I also know Nik-Sil need a special hone. If going through the effort of taking the head off I would get new rings that is just me, but in this case not to certain what to do. Not sure if they are lined I would assume they were lined because AL is pretty soft stuff.
2) If we got new rings are they made specific to the cylinder lining ?
3) If these are chrome lined and no honing how well do new rings seal up ?
4) If we are going though the trouble of taking the head off and if there is any damage not noticed by the looking in the I or E should we just buy an engine kit like off ebay assuming the rings and cylinder are compatible.

Any ideas please share. This saw is rough around the edges but was a good cutter with the 18" bar. Hope we can rebuild it

 

[pantelis]

Good luck

i want to rebuild my grandmother and make her 20 years old , but she is 95

Dont spent your money and your time with bull........ looking for a new or for a good second hand saw, here many members have super saws for sale and in a very reasonbly prices. take a look in the trade post and sure you find something.

 

[lone wolf]

14 yr old son and I cut firewood for our home. His goto saw is a Stihl 026 which use to run very well. latley it has been having issue to continue running. We tweaked on the carb and needless to say it got worse. I will start but will NOT idle at all if WOT it will go to about 8000RPM then quits. Cleaned carb reinstalled and no change. Blocked off the I and E. applied vacuum and pressure to the impulse line and it was 0. Figure it is time to give the saw a good going over refresh install new crank seals, fuel, impulse line, maybe new intake boot. Basically taking it all apart for a good cleaning and freshen it up. Presently looking through the I & E piston and rings looks pretty good do not have a compression gauge that will work on the saw but visually look nice. Son wants to take the head off and port and polish as well as modify the muffler 1 hole to 3 or 4. Wants to make it run a lot better.
1) If we take the head off if we see any damage and must get piston or rings do we rehone the cylinder ?
NOT sure if the 026 is chrome, or NIK-SIL. or how to tell. I assume Nik-Sil would see honing marks but not to sure with chrome or if just AL. I also know Nik-Sil need a special hone. If going through the effort of taking the head off I would get new rings that is just me, but in this case not to certain what to do. Not sure if they are lined I would assume they were lined because AL is pretty soft stuff.
2) If we got new rings are they made specific to the cylinder lining ?
3) If these are chrome lined and no honing how well do new rings seal up ?
4) If we are going though the trouble of taking the head off and if there is any damage not noticed by the looking in the I or E should we just buy an engine kit like off ebay assuming the rings and cylinder are compatible.

Any ideas please share. This saw is rough around the edges but was a good cutter with the 18" bar. Hope we can rebuild it

Maybe the piston and rings are fine get a compression test done before you spend money on a piston and cyl.

 

[pioneerguy600]

Get the saw sealed up tight so that it holds vac and pressure test. Get it running and tuned correctly, it likely does not need the cylinder pulled off if you cannot see and damage. You won`t get any gains porting a 026 unless you really know what to do to them but do a muffler mod, an extra 3/4 " hole is all that`s needed on them. The cylinder is nicasil plated, don`t hone it as that fills the microscopic pores of the nicasil with junk from the hone. The bore can be cleaned with Scotchbrite if necessary, to remove any aluminum smears from a piston. I see the insides of around 8 - 10, 026`s a year, very good 50 cc saws.

 

[MarylandGuy]

Dont spent your money and your time with bull........ looking for a new or for a good second hand saw, here many members have super saws for sale and in a very reasonbly prices. take a look in the trade post and sure you find something.

I can only guess you have never rebuilt a saw. Especially a saw as nice as the old 026. There is nothing on that saw that can't be fixed. And plenty of used parts available, as well as new OEM parts.

Great advice from (almost) everyone so far. Refresh the saw and run it another ten years. If the cylinder ends up being scored, there are countless threads on cleaning up the aluminum scoring (transfer) and installing new piston and rings. It's a very easy saw to work on.

 

[Mad Professor]

If you pull the cylinder at least put a set of rings in it. Examine the piston well and check the clearance at the skirt. If it is sloppy replace it along with an upper rod bearing. The OEM piston kits are now pretty inexpensive. The cylinder is most likely fine if it looks good through the intake/exhaust. I would also give it new hoses, seals and filters. Make sure you have, or purchase, a carb with an adjustable hi speed jet before you open up the muffler.

Well worth fixing right when an equivalent saw new is big $$$

 

[lone wolf]

Get the saw sealed up tight so that it holds vac and pressure test. Get it running and tuned correctly, it likely does not need the cylinder pulled off if you cannot see and damage. You won`t get any gains porting a 026 unless you really know what to do to them but do a muffler mod, an extra 3/4 hole is all that`s needed on them. The cylinder is nicasil plated, don`t hone it as that fills the microscopic pores of the nicasil with junk from the hone. The bore can be cleaned with Scotchbrite if necessary, to remove any aluminum smears from a piston. I see the insides of around 8 - 10, 026`s a year, very good 50 cc saws.

Best advice yet.

 

[Wood Doctor]

Just one simple suggestion that might solve the problems. The carburetor's filter screen might be clogged, robbing fuel flow at both idle and WOT. All you have to do is clean it. I've sometimes done this with an old toothbrush and not even removed the screen from the carb.

You have to remove the carb from the saw to get to the filter screen. Then remove the side of the carb with the large screw. Take a shot a this before you do anything else major to the engine.

 

[bowtieman427]

Great info so far. I really do think this saw is worth refreshing. Like I said it ran great and cut great for a 10lb saw. Son absolutely loves this saw. Right now I do NOT want to pull the cylinder, but want to reseal the engine. Are the chance low that the head gasket is leaking ???

It has the original carb Walbro carb with L, LA, and H adjusters. I ordered an OEM kit for the carb with new screen, needle and seat also. I redid the carb last year and took it apart and cleaned after the issue arose. It still maybe the carb.
I hate to ask any good ideas on where to get a compression tester for chain saws. I have a craftsmen and the fitting that threads in is to long. I used friend that was a push in but he suspect was not accurate because the rubber seal is all dry rotted and cracked. it read 120 on his but like I said not very accurate due to poor sealing.

 

[Wood Doctor]

Great info so far. I really do think this saw is worth refreshing. Like I said it ran great and cut great for a 10lb saw. Son absolutely loves this saw. Right now I do NOT want to pull the cylinder, but want to reseal the engine. Are the chance low that the head gasket is leaking ???

It has the original carb Walbro carb with L, LA, and H adjusters. I ordered an OEM kit for the carb with new screen, needle and seat also. I redid the carb last year and took it apart and cleaned after the issue arose. It still maybe the carb.

OK, it's probably not the carb if you did all that work already. If the head gasket was leaking air, you would probably be running lean and not be able to idle down below 4000 RPM, regardless of carb settings. WOT would likely still work, but the carb setting might influence that. Head gasket could be the problem, but if you are going to do that, you might as well rebuild the top end.

Do a compression test next if you can. Lacking a gauge, hold the saw by the pull cord handle and see if the saw's weight will drop the pull cord once you start it turning with a small downward push. If it keeps dropping, the compression is too low and you need an overhaul.

 

[Mad Professor]

Make sure your parts are back in the carb correct and that it seals up on the intake.

Take a look over the kill switch and coil wires, intermittent shorts can also cause funny running that will give you fits. Worn AV mounts can pinch one of these wires.

If it has not been apart probably not base gasket, but easy to check the cyl screws being loose.

Pres/vac test would be in order if obvious does not remedy things. On a 026 always good to freshen up seals if you do much work or plan on keeping it.

P.S. a bad plug can also cause problems, one more thing you'd replace anyway

 

[Bilge Rat LT 20]

If the push in type compression tester was reading 120 you should have good compression.

When you clean the carb put it in a ultrasonic cleaner. It will get into the tiny passages and get them clean.
Do not blast it with compressed air.
The fuel filter in the tank, fuel line and impulse line should be replaced in that old saw if they have not been replaced in the last few years.

A new carb would only be about 60.00 if you have good compression and spark.

Make sure you have a good seal on the intake and exhaust when doing a press/vac test. Is the impulse line in good shape and attached to the nipple?

 

[ashtuzhed]

The bore can be cleaned with Scotchbrite if necessary, to remove any aluminum smears from a piston.

 

[drf255]

Make sure your exhaust screen isn't clogged up first.

The 026 is not a tough saw to work on.

There's 2 different bores though, a 44 and a 44.7mm. There's a guy selling new OEM 44.7 piston and rings on eBay for $25. I grabbed one.

Stihl Cylinders are Nikasil plated. They don't need a bore and cross hatching like a cast iron cylinder does. They usually hold up quite well and don't need replacement, even if they looked scratched. It's generally aluminum transfer from the piston. They seem to have a propensity to wear down the piston skirt on the exhaust side, sometimes going straight through. I have one that did that and have seen multiple ones do it.

If you have time and aren't dependent on the saw, disassemble carefully and take lots of pics. The guys here will guide you through a rebuild.

 

[mels]

What's your 20? Maybe one of us is close enough where we could meet up with a compression tester and give you some peace of mind.

 

[hardpan]

The good folks here have given a great list of specific tips for your saw. When you are done with repairing and replacing parts you will need good gas, good oil, and the correct tuning procedure. Brad has a fine collection of tuning videos.
http://www.arboristsite.com/community/threads/chainsaw-tuning-101.250802/

 

[bowtieman427]

Hi guys I am in SE MN USA. Near Rochester, MN

 

[pantelis]

I can only guess you have never rebuilt a saw. Especially a saw as nice as the old 026. There is nothing on that saw that can't be fixed. And plenty of used parts available, as well as new OEM parts.

Great advice from (almost) everyone so far. Refresh the saw and run it another ten years. If the cylinder ends up being scored, there are countless threads on cleaning up the aluminum scoring (transfer) and installing new piston and rings. It's a very easy saw to work on.

You guess correct my friend , CONGRATULATIONS. i have never rebuild a saw ,

 

[Mad Professor]

A nice simple saw to work on. Get a T27 torx, screwdiver set, nylon rope for a piston stop, and a flywheel puller. You can make a piston holder of wood, cheap. Use a toothbrush handle, a bit sharpened, to get the rings in. A piece of string to pull the intake boot (rayon/knitting) into the hosuing. Guides here if your seals are bad or you need to make a tester, 026 seals are small and hard to replace.

Try to keep all in place, in and out, match up any new parts. Clean the whole works BEFORE you take apart, keep water out.

Best of luck MP

 

[glock37]

If at wot check choke not being sucked close weak spring in filter There was a thread on this that randy did on my 026 doing 152000 ported


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