026 arguing with me.

[SteveSr]

Would you have a part number for the kit?

My 1999 IPL shows 1121-020-1209 for a 44mm piston. THis may be why you aren't finding rings only at any dealer but might find the piston kit. If not, the dealer can easily order it.

BTW, you are seriously hurting yourself by trying to rush through and throw parts at this saw. That saw was made starting in 1995 making it close to 25 years old. Rubber rots with age. At this point I would do a complete tear down to the crankcase level and check EVERYTHING. Replace all of the critical rubber with OEM while it is still available from Stihl. The good news is that your cylinder is in good shape and can be reused.

The best carb for this saw is a Walbro WT-426 or a WT-194. The 426 limits the adjustment range somewhat which makes it easier to tune while the 194 is fully adjustable. This will be a great saw once it has been rebuilt properly.

 

[DERaffle]

My 1999 IPL shows 1121-020-1209 for a 44mm piston. THis may be why you aren't finding rings only at any dealer but might find the piston kit. If not, the dealer can easily order it.

BTW, you are seriously hurting yourself by trying to rush through and throw parts at this saw. That saw was made starting in 1995 making it close to 25 years old. Rubber rots with age. At this point I would do a complete tear down to the crankcase level and check EVERYTHING. Replace all of the critical rubber with OEM while it is still available from Stihl. The good news is that your cylinder is in good shape and can be reused.

The best carb for this saw is a Walbro WT-426 or a WT-194. The 426 limits the adjustment range somewhat which makes it easier to tune while the 194 is fully adjustable. This will be a great saw once it has been rebuilt properly.

Hey SteveSR, Thanks for the reply and for the manuals. Your's are more up to date than the ones I found. I take your point about rushing, I am slowing down on it to allow for a learning curve. I have replaced all of the rubber (all OEM parts) and am disassembling the rest to inspect. I suspect a vacuum leak but need to get the cylinder back on to test. BTW, this machine was manufactured mid 2000. When I was at one of the dealers looking for parts, a guy offered me a non-PRO 026 cheap that needed a brake handle and runs well (manufactured 1998). I think this is how a collection begins. LOL
I was wondering which Walbro you prefer. I did get a WT-194 but was wondering about the WT-426. Now that I have 2, I could get another as the non-PRO also has only an "L" adjustment on the carb. I am enjoying working on these.
Again, thanks for the input.

 

[SteveSr]

Hey SteveSR, Thanks for the reply and for the manuals. Your's are more up to date than the ones I found. I take your point about rushing, I am slowing down on it to allow for a learning curve. I have replaced all of the rubber (all OEM parts) and am disassembling the rest to inspect. I suspect a vacuum leak but need to get the cylinder back on to test. BTW, this machine was manufactured mid 2000. When I was at one of the dealers looking for parts, a guy offered me a non-PRO 026 cheap that needed a brake handle and runs well (manufactured 1998). I think this is how a collection begins. LOL
I was wondering which Walbro you prefer. I did get a WT-194 but was wondering about the WT-426. Now that I have 2, I could get another as the non-PRO also has only an "L" adjustment on the carb. I am enjoying working on these.
Again, thanks for the input.

The non-H adjustable WT-403 was known to have fuel pooling issues at idle where dropping the nose of the saw to release the chain brake would cause the saw to stall. I sent a saw back to Stihl because of this.

Removing the seals, especially on the FW side can cause 4-letter words and gray/missing hair. The object is to get the old seal out without scratching the crankshaft or buggering the the crankcase bore. Stihl makes a special tool for this which is rather spendy. When using the tool the secrets are to first loosen the seal in the crankcase by using a drift to slightly drive it in all the way around. The second secret is to use an x-acto knife to remove the existing rubber to give the pulling lips on the tool something to grab onto. The other option is to find a dealer with the tool (and knows how to use it) and take them a clean crankcase and let them do it. Should be pretty inexpensive. When installing the new seals be sure to spread a small amount of Dirko sealant around the outside of the seal to prevent any leaks at the crankcase interface.

Cylinder on is the best way to clean these up as you only have to block off the exhaust with a plate and duct tape and hose clamp around the intake. This keeps any crud out of the crankcase. Then give it a kerosene/diesel bath followed by a simple green final wash and rinse. I usually do this before even the first pressure test.

While you are at it I would also do a partial disassembly of the oil pump to get rid of any crud that may have accumulated in it. This is done by pressing out one roll pin, sliding the adjustment shaft back, and allowing the piston to move out about 3/16". Then flush it with carb or brake cleaner.

 

[1hander]

hey boss
sorry for your troubles but your on the right track, after looking at your pics...darn good pics btw...
that reading of 40psi def is weird.. i tried a HF comp tester too...and all my saws showed exactly 44psi..LOL
turned out the fitting where the hose connects to the gauge was machined too short and leaking..
long story short..HF comp tester equals JUNK

i have a weedeater that needs a rebuild with 48 psi comp, takes 20-30 pulls but it will start and run, once LOL
i found an old Actron comp tester deep in the tool box and they sell them on ebay and they are dead nuts accurate
looking at the pics...the piston and rings are for sure done..
if you can run your finger nail down the side of the piston and not feel the machined grooves, its a throw away
once you start getting all that blowby the carb doesnt know wtf to do .

if the cylinder has no scarring, id say theres no reason you can use it one more time. with new piston and rings..
if you can find the set, replace it all of course.
the reason i say reuse is that i just rebuilt an 015L and 08s, (these saws are older than yours i think) both with original cylinders, using new stihl piston and rings the 015L tested at 178 psi and after 8 tanks its sitting at 170-175psi.....the 08s tested at 188 or so, after 8 tanks sitting at 185ish psi.
if you can find stihl piston and rings definitely go with that you wont regret it.

if you decide to reuse the cylinder, some will say im crazy, but thats ok, the doctors said the same thing
what i do when i reuse cylinders is use some 180-220 sandpaper,
a small piece about fingers length and i manually , put a crosshatch back into the chrome lining
first at an angle in one direction, working my way all the way around the cylinder...then the other direction to get the crosshatch
too hard and youll ruin the liner, after that , i use a fine scotchbrite pad and repeat the pattern (lightly)to knock down sharp edges
then wash it out real good before install..

once you get it all sealed up again, youll have a strong running saw and the effort you made will have been worth it..
all the best

 

[DERaffle]

FYI.
I returned my Harbor Freight compression tester and purchased one from Tiny Tac ($50). Just got it today, a very nice and well made piece. I checked my 031 and my other newly acquired 026 with the HF gauge, both in the 40lb range. With the new Tiny Tac, 031 @ 150+ and my 026 @160+.
Moral of this chapter of the story... HF compression gauge no good for chainsaws.

Still waiting for new rings...

 

[SteveSr]

Still waiting for new rings...

Be sure to check piston skirt clearance if reusing the old piston. Stihl doesn't publish absolute numbers but other folks here can give you a ball park max clearance numbers.

 

[DERaffle]

Be sure to check piston skirt clearance if reusing the old piston. Stihl doesn't publish absolute numbers but other folks here can give you a ball park max clearance numbers.

Thanks for the reply Steve. Hopefully someone can give me the clearance numbers.

 

[DERaffle]

Thanks for the reply Steve. Hopefully someone can give me the clearance numbers.

I can still feel the machining (for the most part) on the original piston.

 

[TheTone]

now im waiting for some stuff to show up in the mail, i got the starter cover but got lied to ,,,damn thing is missing some fins, im gonna see if it can be welded , by using some fins from an old busted starter cover to fill in the missing ones..

Thanks for the reply Steve. Hopefully someone can give me the clearance numbers.

New .002 -. 0025, reuse: .0025 - .003, iffy (depends on circumstances - your saw or customer saw) .003 - .0035, replace: .004 or more. Also consider machining marks - they help hold oil on the piston. These are my guidelines, others may use different specs. I would reuse a piston for my own saws if between .003 - .004, and it looked good, i.e., not smooth.

 

[DERaffle]

So I pulled the clutch and the flywheel, temporarily reinstalled the jug (still waiting for rings) and checked the seal with a homemade pressure tester and soapy water. The clutch side seemed to sealed and the flywheel side leaks like a sieve.
Couple of questions:
Should I replace both or just the one side? (I did buy them both)
How intimidated should I be by removing/reinstalling the seals?
Should I take it to a local dealer to have them replaced?
Input would be greatly appreciated.

 

[gmctyphoon]

Replace both. YouTube is your friend.
One thing I seem to always forget when changing seals is to make a note of where the factory ones are seated before I take them out. (At what depth they are seated)

 

[DERaffle]

So I put the new seals in yesterday. They actually came out pretty easily with a notched screwdriver. Took everyone’s advice and altered a perfectly good Klein screwdriver rather than a cheap one, used a crescent wrench as a driver. Put the new seals in and pressure tested in with no leaks. Got my new OEM rings today and installed them tonight. Everything went back together well with no leftover parts. (Lol) It helped that I had the other 026 for reference. Compression tops out at 160+ cold.
I didn’t try to start it yet but I have a question. Are there any special things I should be doing since I put in the new rings? Any type of break in protocol I should follow? Looking forward to testing it out in the morning.
Thanks in advance for the input.

 

[John Lyngdal]

I lightly coat the cylinder wall, piston skirt, and piston wrist pin bearing with straight mix oil and then assemble.
A little extra mix oil down the spark plug hole is a good "Plan B".
It might smoke a bit when you first start it, but it will clear up quickly.

 

[gmctyphoon]

I also pour about a half cap full of 2 cy oil down the spark plug hole. Then I pull the starter a couple times without the spark plug in to get the oil everywhere.
Then start the saw up like normal. Will smoke for a minute or two.
Congrats on getting the saw back together!

 

[Okie294life]

When you put the head back on I would check the torque on the head bolts. One common thing that happens with old saws is someone will over torque the head bolts stripping out the delicate casing threads. If you get it back together and one is stripped, or it takes over 80-90 inch lbs, to get it down it’s clapped out and probably only good for parts, or rebuild.

 

[DERaffle]

When you put the head back on I would check the torque on the head bolts. One common thing that happens with old saws is someone will over torque the head bolts stripping out the delicate casing threads. If you get it back together and one is stripped, or it takes over 80-90 inch lbs, to get it down it’s clapped out and probably only good for parts, or rebuild.

I only used the Stihl “T” driver. I put it tight but not overly so. Should I back it off a bit? Does it stress it more when it runs? I wouldn’t think I could easily over tighten with the T.
Thanks for the input!

 

[Okie294life]

I only used the Stihl “T” driver. I put it tight but not overly so. Should I back it off a bit? Does it stress it more when it runs? I wouldn’t think I could easily over tighten with the T.
Thanks for the input!

Get a little torque wrench from autozone that reads in lb. Some of the dudes on here have their wrist calibrated, but I’m not that good. If you did tighten the bolts down and didn’t feel them slipping you are probably ok. Usually you can tell when ones stripped pretty easily. One of the tell tell signs is after it has ran and cooled down check head bolts again 2-3 times with a torque wrench. Sometimes they will grab but don’t have enough thread left to keep the bolts from backing out while the saw is running. It’s frustrating because the saw may even pass a pressure test, then after it runs a couple times it craps out.if you can’t keep the head bolts from backing out even after retightening a couple times that’s your culprit.

 

[drf255]

So I put the new seals in yesterday. They actually came out pretty easily with a notched screwdriver. Took everyone’s advice and altered a perfectly good Klein screwdriver rather than a cheap one, used a crescent wrench as a driver. Put the new seals in and pressure tested in with no leaks. Got my new OEM rings today and installed them tonight. Everything went back together well with no leftover parts. (Lol) It helped that I had the other 026 for reference. Compression tops out at 160+ cold.
I didn’t try to start it yet but I have a question. Are there any special things I should be doing since I put in the new rings? Any type of break in protocol I should follow? Looking forward to testing it out in the morning.
Thanks in advance for the input.

You should have extra oil in there from assembly already.

I open the H screw 2 turns out and start the saw. Adjust L and LA screws. A few blips to WOT to see if it sounds super fat or not. Adjust H.

Keep it on the fatter side of tune.

Then bury the bar and load saw as much as you can to make the rings seat into the bore. Make 4-5 cuts.

It’s not like a car engine break in. On saws you really should “run it like you stole it” IMHO-others will have different opinions.