Stihl 026 Pro carb adjust & swap

[Rusted]

Hey all, I've been reading for a while and a first time poster.

After shopping around for a used light weight saw and all the good things I've read, I narrowed it down to a couple of Stihl saws, ending up with a Stihl 026 Pro. It passed the basic checks and ran okay on a log slice test with a dull chain. My old abused back likes the feel of this saw, and I bought it expecting to put a few bucks into it. I kind of know the seller through friends. He's original owner, showed me tune up & receipts from the shop that put a new carb in it (original type carb). He fell tress with it the week before a few miles down the road of me, with no issues. He said he was making sure he sold me a healthy saw considering our mutual friends. Once I got it home, I decided to feel it out on some logs. It ran great for a few minutes and then ran worse and worse. I didn't add fuel, bar oil or anything since it was topped off with fresh when I tested it by the owner. I can get it running, but it bogs out and dies when I throttle. How many times have you heard that one? Ha!

This is the first Stihl I've owned (but not used). It has the older carb with the auto adjustment and only one adjustment screw where the H/L would normally be in most models - you know the one. I've tried tweaking it and resetting to factory. It runs but struggles and dies with any throttle. Even after I let off the throttle quickly it doesn't go back to idle, it dies. Tank breather valve's fine, I just can't get this sucker dialed in at all and I really need it since my other saw is loaned out and too far away to go fetch it right now.

I'm looking to order the Walbro WT-194 (-1) carb to replace this one for all the reasons I learned on this site thanks to you guys. I'd like to stick with Walbro if I can for reliable quality and adjustment options. I usually run 40:1 and hoping that's not an issue for a Stihl that says 50:1. So far it looks like $70 on Ebay is the ticket, does that sound about right? Prices really vary and that makes me wonder if I buying smart or not? If there's better or anything to avoid, I'm all ears and open to suggestions.

While I have it opened up, is there an over all maintenance kit for this saw to replace worn parts for a good clean start? (Fuel lines, filter. rubber boots, some seals, condenser, plug, etc) Or is there a list out there I could use?

Long story short, we had a snow storm and now I need the saw asap with trees down. Does anyone have suggestions how to adjust or get this saw running with the old carb on it so I can use it until the new one comes? It's got to be something I'm not seeing or is different if this saw ran so well a week before and when I tested it too. IDK... just my luck I guess?

Thanks in advance and for your time and I appreciate anything offered.

 

[RED-85-Z51]

If start with inspecting the fuel line, the accordion line was prone to cracking. Then inspect the intake boot for cracking...026 is getting pretty old, rubber can crackm

Sent from my LM-G820 using Tapatalk

 

[Okie294life]

Get that carb apart and check the little screen inside it, if you have any skills rebuilding carbs. Check the fuel line and boot first for leaks obviously because it could be sucking air. If you take care of all 3 of these and the gaskets aren’t shot it should run as long as the carb jets are at default settings

 

[Rusted]

Okay, I'll have a 'much' closer look then as I may have put too much faith in the previous owners idea of serviced. I'd hoped there would be a quirt of that type of carb I didn't know or an adjustment I wasn't seeing. Didn't know about a screen in the carb either, will have a looksie. The gas in it's still 50:1 from the previous owner. I wonder if 40:1 is going to run right on that less adjustable carb? Thank you!

 

[Okie294life]

Okay, I'll have a 'much' closer look then as I may have put too much faith in the previous owners idea of serviced. I'd hoped there would be a quirt of that type of carb I didn't know or an adjustment I wasn't seeing. Didn't know about a screen in the carb either, will have a looksie. The gas in it's still 50:1 from the previous owner. I wonder if 40:1 is going to run right on that less adjustable carb? Thank you!

50-40 won’t make that much of a difference if it’s got stale gas get it out. As long as you use stihl ultra or some other kind of decent mix you’ll be fine with some non ethanol gas of course

 

[drf255]

Start with the basics. Pull muffler and check piston, then do a vac test. Make sure muffler screen isn’t plugged.

 

[pioneerguy600]

The 026`s are fine saws when running properly but I don`t like what I read in your description of how the saw acted when you ran it. First thing I do is pull the front off the muffler, look at the piston for scoring. Never run a chainsaw on someone elses mixed fuel.

 

[1hp]

if you can do a pressure test, do it. my 026 pro had similar symptoms. ended up being the plastic bearing cages had disintegrated and needed new crank seals.

 

[AKTrailDog]

Hey all, I've been reading for a while and a first time poster.

After shopping around for a used light weight saw and all the good things I've read, I narrowed it down to a couple of Stihl saws, ending up with a Stihl 026 Pro. It passed the basic checks and ran okay on a log slice test with a dull chain. My old abused back likes the feel of this saw, and I bought it expecting to put a few bucks into it. I kind of know the seller through friends. He's original owner, showed me tune up & receipts from the shop that put a new carb in it (original type carb). He fell tress with it the week before a few miles down the road of me, with no issues. He said he was making sure he sold me a healthy saw considering our mutual friends. Once I got it home, I decided to feel it out on some logs. It ran great for a few minutes and then ran worse and worse. I didn't add fuel, bar oil or anything since it was topped off with fresh when I tested it by the owner. I can get it running, but it bogs out and dies when I throttle. How many times have you heard that one? Ha!

This is the first Stihl I've owned (but not used). It has the older carb with the auto adjustment and only one adjustment screw where the H/L would normally be in most models - you know the one. I've tried tweaking it and resetting to factory. It runs but struggles and dies with any throttle. Even after I let off the throttle quickly it doesn't go back to idle, it dies. Tank breather valve's fine, I just can't get this sucker dialed in at all and I really need it since my other saw is loaned out and too far away to go fetch it right now.

I'm looking to order the Walbro WT-194 (-1) carb to replace this one for all the reasons I learned on this site thanks to you guys. I'd like to stick with Walbro if I can for reliable quality and adjustment options. I usually run 40:1 and hoping that's not an issue for a Stihl that says 50:1. So far it looks like $70 on Ebay is the ticket, does that sound about right? Prices really vary and that makes me wonder if I buying smart or not? If there's better or anything to avoid, I'm all ears and open to suggestions.

While I have it opened up, is there an over all maintenance kit for this saw to replace worn parts for a good clean start? (Fuel lines, filter. rubber boots, some seals, condenser, plug, etc) Or is there a list out there I could use?

Long story short, we had a snow storm and now I need the saw asap with trees down. Does anyone have suggestions how to adjust or get this saw running with the old carb on it so I can use it until the new one comes? It's got to be something I'm not seeing or is different if this saw ran so well a week before and when I tested it too. IDK... just my luck I guess?

Thanks in advance and for your time and I appreciate anything offered.

So I'm interested in what the receipts state. You say you have some from the shop. What did they actually do, install a new carb? What was involved in this tune up? Start there before even looking at the saw. Once you have the knowledge of what work was said to be done, then start diagnosing the issues. Like others have stated, start simple. What does the saw need to run? Spark, fuel and air. Of course all at proper levels. If I have a saw that's running as such, I change and/or inspect the fuel filter, air filter, cracks in fuel lines, check impulse line, check for strong spark and make sure the carb settings are proper. The L adjustment setting is very fine tuned and any small adjustment will make it run poorly or at it's sweet spot. Make sure the LA adjustment is set properly too with this. If that is set too far out (too many turns counterclockwise) it won't run properly. Turn it clockwise all the way til the chain starts spinning and then back it off til it's not spinning. If after all this and if it's still not running correctly I'd start getting into the carb and the diaphragm or needle jet etc etc. Taking the muffler cover off (as mentioned) is a quick thing to do and check the muffler screen for clogging, to check the piston for scoring etc. Then you start getting deeper into things.

I just acquired (2) 026s and one wasn't running correctly. The impulse hose was just about not connected and loose, had a cracked fuel line. I installed new fuel filter, fuel line and air filter, set the carb to factory settings and put the tach on it to tune it correctly. I also pressure and vacuum checked everything but I realize not everyone is able to do that without proper tools. Runs like a champ and the saw is 20+ years old.

Keep it simple til it's been ruled out.

 

[SteveSr]

I'm looking to order the Walbro WT-194 (-1) carb to replace this one for all the reasons I learned on this site thanks to you guys. I'd like to stick with Walbro if I can for reliable quality and adjustment options. I usually run 40:1 and hoping that's not an issue for a Stihl that says 50:1. So far it looks like $70 on Ebay is the ticket, does that sound about right? Prices really vary and that makes me wonder if I buying smart or not? If there's better or anything to avoid, I'm all ears and open to suggestions.

If this is the actual later production "Pro" model with the compensating carb you'll need either a WT-394 or a Wt-426 carb. A 194 can be made into a 394 with a metering cover swap. I tend to like the 426 better as it is not as "touchy" to adjust as the 194/394 is.

 

[Rusted]

If this is the actual later production "Pro" model with the compensating carb you'll need either a WT-394 or a Wt-426 carb. A 194 can be made into a 394 with a metering cover swap. I tend to like the 426 better as it is not as "touchy" to adjust as the 194/394 is.

The first round I checked the basics like the lines, cleaned air filter (filthy), checked muffler (clear), wiring (visually no cracks, bad connections, rubbed bare or melting), visual check (not removed) on carb venturi and choke was free and clean. Plug looked good and double checked checked gap. I'm making a list of the suggestions, I'll do them all systematically tonight and see what I can find. I can do a compression test, but not vacuum. I back shelved the compression test being pressed for time since it felt so strong I didn't bother, but I'll get on that. Pulling the carb apart, should I get new seals?

The owner did put fresh fuel in it for the test so I left it in at home thinking I'd add after running it out. But I know you're right. Typing it now, I hear that voice in the back of my head telling me the obvious, which I was ignoring. Ha!

The receipt was from a local shop + original sales receipt. Nothing too detailed. They did a tune up / inspection and replaced frayed pull cord (which I' need to adjust as it doesn't recoil right) and replaced the carb. He did say it sat for while with fuel in it and wouldn't start and the reason he took it in. He said they wanted to rebuild the carb, but he insisted on a new one. Since being asked, I looked closer at the receipt and the carb's 11 months old so I'm wondering now if it sat again? I am a couple hundred feet higher elevation than the initial test run was, but I'd think I could adjust for that. The idle adjusts very well, I back it off until the chain stops as suggested etc. It runs strong BUT with an uneven idle. Is that uneven idle normal? My last saws didn't, maybe that's a clue? When I find the issue, I feel like it's going to be a 'Duh' moment and I'll certainly let you guys know. I'm am mechanically inclined, but weak on 2 cycle engines - learning. When I worked for landscape outfits, I treated my saw right and got more life out of them than most. Getting so lucky never having any issues I easily couldn't fix kept me from learning anything beyond that. So, I really do appreciate all the help here!!


I ordered a Walbro WT-194-1 after writing my thread last night being so sure that was the right one. Soooo, okay you're saying it won't work? I swore that was the one to buy from all my research. I did consider the pro being different but read that it didn't affect the carb choice and you could keep the air filter if you plugged the extra hole? I've been reading randomly for two weeks, but I must have gotten something mixed up and in too much of a hurry. I'm still going to try and get it running as it is for now so I can use it on the trees that fell during our storm. Meanwhile, I'll do some digging and if there are any threads or further input anyone would care to add for the correct carb upgrade, I'd greatly appreciate it. Thanks for bringing that up!

 

[Rusted]

I looked around and I'm finding Walbro's WT-426 are priced all over the board from $15 to $80 and so on. Is there a right and wrong option if it says it's a Walbro? Will the 426 handle any basic mods I might do down the road? Do I need a new air filter and anything else to adapt it?

If I need to stick to getting the old carb running and start a new separate thread on the upgrade, just let me know. I'm not as tech savvy as I wish I was and I haven't done but a handful of threads. A late starter.

 

[SteveSr]

Sorry, we are not very good mind readers here. Some photos of the saw/carb or model numbers would help. Stihl made many different versions of this saw over 20 or so years. The quality of any advice is going to highly depend on knowing which version you actually have. A new carb shouldn't need to be replaced unless it sat with corn gas in it for a year.

 

[pioneerguy600]

I put 194`s on every 026 and MS260 that comes my way, somewhere around 35 by now. If a carb requires the snorkel just take the one from the carb you have now, not saying the carb you have has the snorkel as I have seen no pics posted yet. If you pull the front cover off the muffler and check the piston I would not worry about a compression test just yet. If the piston is scored you have to pull it anyway so a comp test won`t help. Dirty carbs will usually idle but not rev up, not always if the low L orifices are completely blocked. Its usually the fine screen that gets blocked up with debris but some fuel can get past to let the engine idle, just restricts the flow enough so the engine cannot rev up. A plugged up muffler screen acts much the same way, engine will start and idle but not rev up.

 

[o_o]

So I'm interested in what the receipts state. You say you have some from the shop. What did they actually do, install a new carb? What was involved in this tune up? Start there before even looking at the saw. Once you have the knowledge of what work was said to be done, then start diagnosing the issues. Like others have stated, start simple. What does the saw need to run? Spark, fuel and air. Of course all at proper levels. If I have a saw that's running as such, I change and/or inspect the fuel filter, air filter, cracks in fuel lines, check impulse line, check for strong spark and make sure the carb settings are proper. The L adjustment setting is very fine tuned and any small adjustment will make it run poorly or at it's sweet spot. Make sure the LA adjustment is set properly too with this. If that is set too far out (too many turns counterclockwise) it won't run properly. Turn it clockwise all the way til the chain starts spinning and then back it off til it's not spinning. If after all this and if it's still not running correctly I'd start getting into the carb and the diaphragm or needle jet etc etc. Taking the muffler cover off (as mentioned) is a quick thing to do and check the muffler screen for clogging, to check the piston for scoring etc. Then you start getting deeper into things.

I just acquired (2) 026s and one wasn't running correctly. The impulse hose was just about not connected and loose, had a cracked fuel line. I installed new fuel filter, fuel line and air filter, set the carb to factory settings and put the tach on it to tune it correctly. I also pressure and vacuum checked everything but I realize not everyone is able to do that without proper tools. Runs like a champ and the saw is 20+ years old.

Keep it simple til it's been ruled out.

Hi! What is the “proper” setting for the H jet on the 026 pro carb?

 

[Vintage Engine Repairs]

The proper setting is where Is runs correctly rather than a fixed position. Too many variables. This video should help.

 

[o_o]

The proper setting is where Is runs correctly rather than a fixed position. Too many variables. This video should help.

This was exactly the video I needed to see thank you!

 

[Vintage Engine Repairs]

Glad it helped

 

[AKTrailDog]

This was exactly the video I needed to see thank you!

Hi there, good video and information. Sorry for no response, haven't been on here for a bit.

I also use a tachometer when tuning my saws regardless of how long I've been doing it. Its nice to put a number to the sound with regard to the rpms whether at idle or on the high end.