026 Stihl surging and bogging.

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The best thing to do with these is to just drill out the tank with a 15/32" bit. There is access through the top of the carb box once you remove that metal cover. I have done several like this. The old fuel line is likely NLA while the new one is the same as used on the 260 and should still be available for a while.

Im glad I saw this before I took it back. Nice tip!
 
Im glad I saw this before I took it back. Nice tip!

Also I don't know which fuel pickup you have but I believe that the new hose is intended to use the "large" barb pickup. If you haven't got one of them you may need to get one.

Some of the older style pickups had foam in them that would decompose and crumble and end up in the carb screen and cause all sorts of problems. The pickups come apart with a small screwdriver for inspection. You can use a drill press arbor or a vice and small socket to snap them back together.
 
Well either the fuel line or the carb cleaning seems to have fixed it. I cut some logs this afternoon and some small trees down. No bogging and my idle seems to be right. I didn't have my phone with me when I was cutting so I took a video when I got back.



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Good on you for seeing this through, they really are such simple machines.
 
Well I still seem to have some issues. I was cut a few trees down behind the house and everything worked fine. This morning when I started cutting the logs down into firewood length it also ran great for a tank. After that it seemed to start racing one me. Idle seems ok but it acts like it's over revving in the cut. I think I need to pressure test. What do I need to buy to do that? I figure I might as well buy the stuff rather than pay the shop to do it. Especially since the stihl dealer here said it would cost $400 plus to change crankcase seals and if it leaked to just buy a new saw[emoji849]

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Well I still seem to have some issues. I was cut a few trees down behind the house and everything worked fine. This morning when I started cutting the logs down into firewood length it also ran great for a tank. After that it seemed to start racing one me. Idle seems ok but it acts like it's over revving in the cut. I think I need to pressure test. What do I need to buy to do that? I figure I might as well buy the stuff rather than pay the shop to do it. Especially since the stihl dealer here said it would cost $400 plus to change crankcase seals and if it leaked to just buy a new saw[emoji849]

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Mityvac8500.

Do a pressure and vacuum test. Some seals pass a pressure but not a vacuum and vis versa.

Good luck hope you get it solved.

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Well I still seem to have some issues. I was cut a few trees down behind the house and everything worked fine. This morning when I started cutting the logs down into firewood length it also ran great for a tank. After that it seemed to start racing one me. Idle seems ok but it acts like it's over revving in the cut. I think I need to pressure test. What do I need to buy to do that? I figure I might as well buy the stuff rather than pay the shop to do it. Especially since the stihl dealer here said it would cost $400 plus to change crankcase seals and if it leaked to just buy a new saw[emoji849]

Sent from my SAMSUNG-SM-G891A using Tapatalk

Where do you have your H needle set at? The 024 and 026 with a WT194 likes the H set around 1 1/4 turns out from lightly seated, any more than 1 1/2 turns out you have an air leak. Lots of times its the flywheel side seal but can also be the clutch side seal or the intake boot has a leak. Since your fuel line is new I doubt its the problem. Did you install a new in tank pickup filter? Have seen badly degraded and or hardened/clogged up filters cause fuel starvation at WOT.
 
Especially since the stihl dealer here said it would cost $400 plus to change crankcase seals and if it leaked to just buy a new saw[emoji849]

You need to find a NEW dealer! Changing seals ain't bad especially if you have the Stihl special tool. Surprisingly a LOT of dealers don't have the special tool. Without the tool they can be annoying with a risk of scratching the crank.
 
Where do you have your H needle set at? The 024 and 026 with a WT194 likes the H set around 1 1/4 turns out from lightly seated, any more than 1 1/2 turns out you have an air leak. Lots of times its the flywheel side seal but can also be the clutch side seal or the intake boot has a leak. Since your fuel line is new I doubt its the problem. Did you install a new in tank pickup filter? Have seen badly degraded and or hardened/clogged up filters cause fuel starvation at WOT.
I just went and checked. It's just shy of 1 1/4 turns out.

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check the intake boot clamp. had some issuses with my 026. i was getting ready to pull the boot and the clamp was loose.
Clamp screw want loose but did tighten up a few turns.

I'm probably not going to be satisfied until I pressure/vac test. I'm going to pick up a mityvac this week. I see this one listed at Harbor freight. Will it work? https://m.harborfreight.com/mityvac-vacuum-pump-39522.html?utm_referrer=direct/not provided

I'm sure it's not as good as the 8500 but I'm not going to use it that often.

Rubber strips behind the muffler and carb correct? Where do I attach the vacuum pump?

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On the 026 it is best to make a block off plate that fits in place of the carb, then pull vac through the impulse line on lower left of the airbox. If the rubber strip behind the carb is used then you need an adapter to pull vac through the sparkplug hole.
 
Clamp screw want loose but did tighten up a few turns.

I'm probably not going to be satisfied until I pressure/vac test. I'm going to pick up a mityvac this week. I see this one listed at Harbor freight. Will it work? https://m.harborfreight.com/mityvac-vacuum-pump-39522.html?utm_referrer=direct/not provided

I'm sure it's not as good as the 8500 but I'm not going to use it that often.

Rubber strips behind the muffler and carb correct? Where do I attach the vacuum pump?

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That pump only pulls vacuum, and it's the same price that you can find the right tool on-line.
 
Last time I put a new style fuel line on an older style 026, the portion of the fuel line that runs from the tank hole to the carb nipple kept getting a kink in is as I ran the saw. Was behaving just as you described. You might want to check it real close to see if your new fuel line is getting kinked!
 
Fuel line is not kinked. I actually chickened out on drilling the larger hole and swapped the new hose I had for the old style smaller one. I ordered a block off plate from stihl and a mityvac 8500 from amazon. Both came in today. Im going to try and get out to the shop tonight and pressure/vac test.
 
Did the vacuum/pressure test tonight. It will hold 10 psi pressure. I let it sit for 2 minutes and the needle didn't budge. When I did the vacuum test it would drop from 10 to about 8 immediately but would then hold there. I'm not sure what this means? I had my impulse tube blocked with a golf tee, what I wonder is how well it seals when I push the carb into it. No way to really test that?

Piston looks brand new from the muffler and carb side.



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