Stihl 026 Needs New Impulse Line

[quads]

Years ago I bought two 026 saws from a neighbor, for $50. An older one with all the carb adjustments, and one a little bit newer than that which has no high speed mixture adjustment. I refer to it as the newer one, even though it's old too.

I really liked the older one. The newer one never did have the same power, and always seems to run a little bit too rich. The older one was always my favorite; my number one saw. The newer one was just my spare, and I'd run a tankful through it once a year, just for giggles.

One day a few years ago my favorite saw started running too lean and I could not get it to richen, even though it has all the carb adjustments. I assumed that it had a crack in the rubber intake manifold, then put it away and used the spare from that day forward. I always thought maybe someday I'd take it apart and see what I could find, but never have.

There is a little snowstorm today and I wasn't going out to cut wood in it, so today I went to my Stihl dealer to get a couple chains and looked at the new saws. He wasn't busy, I was the only customer there, so we got talking about my old saws. I told him of my problem with my favorite saw and he said that in his experience with 026 it's usually the impulse line that gets a hole in it and makes them run lean, and not the intake manifold.

When I get home the first thing I did was grab it off the hook where it's been hanging for a couple years. I peeked in between the handle and the engine with my flashlight, and sure enough, I could see a little black spot in the brown dust on the line. Blew it all off with the air compressor and the impulse line is very obviously shot.

Now, I need to figure out how to get in there and replace it! Maybe tomorrow after plowing snow I'll get to look at it again. I wonder if it's possible to replace it without taking the carb off? It's hard to even see it back in there.

 

[quads]

From the clutch side, peeking down between the handle and the clutch cover. The hole in the hose, way down there.

From the starter side.

Under the carb. It runs through the plastic.

It looks like it might just be pushed through the plastic under the carb. I'm thinking that I may be able to grab it with my needle nose pliers, or my locking surgical pliers that I use for fish hooks (what are those called? hemostats?) and pull it out of there. The trick would then be trying to install the new one without taking the carb and all that stuff apart.

It would be very nice to get my favorite saw running again! Maybe tomorrow, crossing my fingers.

 

[smokinj]

I hate when it gets that small just dont have the hands for it.

 

[quads]

Me too. Big hands and fingers and I can't get in those tights spots so easily. If I get time, I'll see how it goes today and maybe remember some old cuss words! If I have to, I'll pull the carb off it etc.

 

[kevin j]

Large medical hemostats, a straight tip one and a curved tip one. also good for fishing out fuel filters etc.
I see them a lot on flea markets, cheap tools sales, etc. bins of stainless steel hemostats usually made in pakistan as are a lot of medical stuff. I think it is either reject quality or just massive extra build runs, as they are about $4 apiece. methinks medical grade is a bit more than that..........

 

[billb3]

Large medical hemostats, a straight tip one and a curved tip one. also good for fishing out fuel filters etc.
I see them a lot on flea markets, cheap tools sales, etc. bins of stainless steel hemostats usually made in pakistan as are a lot of medical stuff. I think it is either reject quality or just massive extra build runs, as they are about $4 apiece. methinks medical grade is a bit more than that..........

or your local head shop if they are still legal in your area.
maybe even police auctions

 

[quads]

I got it running. Had to take it all apart to do it though. When I went back to the Stihl dealer to get the hose today, he had one apart on the back bench and showed it to me. Haven't had a chance to do any cutting with it yet, but runs like a champ standing in the driveway.

Now, does anybody know how to slow the bar oil down? That one always did seem like it pumps way more than it has to, it drools all over the place. I would like to turn it down a little. There is a hole in the bottom of the saw, that has a picture of a chain link and an oil drop with an increase/decrease symbol, but the hole goes way up in by the clutch, and I'll be darned if I can find any sort of screw or anything up in there. I even took the clutch bell off and peered back in behind the clutch shoes, but I can't see any adjustment screw.

 

[smokinj]

I got it running. Had to take it all apart to do it though. When I went back to the Stihl dealer to get the hose today, he had one apart on the back bench and showed it to me. Haven't had a chance to do any cutting with it yet, but runs like a champ standing in the driveway.

Now, does anybody know how to slow the bar oil down? That one always did seem like it pumps way more than it has to, it drools all over the place. I would like to turn it down a little. There is a hole in the bottom of the saw, that has a picture of a chain link and an oil drop with an increase/decrease symbol, but the hole goes way up in by the clutch, and I'll be darned if I can find any sort of screw or anything up in there. I even took the clutch bell off and peered back in behind the clutch shoes, but I can't see any adjustment screw.

it either never had one or the screw came out and that I have never seen. Can you see any threads inside the whole?

 

[quads]

I got it running. Had to take it all apart to do it though. When I went back to the Stihl dealer to get the hose today, he had one apart on the back bench and showed it to me. Haven't had a chance to do any cutting with it yet, but runs like a champ standing in the driveway.

Now, does anybody know how to slow the bar oil down? That one always did seem like it pumps way more than it has to, it drools all over the place. I would like to turn it down a little. There is a hole in the bottom of the saw, that has a picture of a chain link and an oil drop with an increase/decrease symbol, but the hole goes way up in by the clutch, and I'll be darned if I can find any sort of screw or anything up in there. I even took the clutch bell off and peered back in behind the clutch shoes, but I can't see any adjustment screw.

it either never had one or the screw came out and that I have never seen. Can you see any threads inside the whole?

Nope, I can't see any threads or place where an adjuster might have fallen out. I looked at my other 026, it has the same hole in the bottom of the saw, but can't see any adjuster in that one either. But that saw uses far less bar oil.

With the saw idling, if I look down at the chain where it comes out of the clutch cover, I can watch the bar oil bubble up through the chain links. Then it dribbles down the bar and drips on the ground, although slowly. That seems like too much to me, and is a lot more than the other 026 uses. I guess it is ok as long as it doesn't run out of bar oil before fuel, but I won't know for sure until I get cutting with it again. Just wish I could figure out how to turn it down a little, if possible.

 

[smokinj]

I got it running. Had to take it all apart to do it though. When I went back to the Stihl dealer to get the hose today, he had one apart on the back bench and showed it to me. Haven't had a chance to do any cutting with it yet, but runs like a champ standing in the driveway.

Now, does anybody know how to slow the bar oil down? That one always did seem like it pumps way more than it has to, it drools all over the place. I would like to turn it down a little. There is a hole in the bottom of the saw, that has a picture of a chain link and an oil drop with an increase/decrease symbol, but the hole goes way up in by the clutch, and I'll be darned if I can find any sort of screw or anything up in there. I even took the clutch bell off and peered back in behind the clutch shoes, but I can't see any adjustment screw.

it either never had one or the screw came out and that I have never seen. Can you see any threads inside the whole?

Nope, I can't see any threads or place where an adjuster might have fallen out. I looked at my other 026, it has the same hole in the bottom of the saw, but can't see any adjuster in that one either. But that saw uses far less bar oil.

With the saw idling, if I look down at the chain where it comes out of the clutch cover, I can watch the bar oil bubble up through the chain links. Then it dribbles down the bar and drips on the ground, although slowly. That seems like too much to me, and is a lot more than the other 026 uses. I guess it is ok as long as it doesn't run out of bar oil before fuel, but I won't know for sure until I get cutting with it again. Just wish I could figure out how to turn it down a little, if possible.

there is 2 kinds of 026 pro and 026 thats what it sounds like you have no other difference other than oil adjustment and decompression

 

[dante2]

Quads sounds like you got the non pro 026 like mine. If yours is anything like mine it leaves a puddle under it after I use it. If yours does this too, try opening the oil cap slightly to let it vent. You can add the adjustable oiler but the parts to do it are not cheap. If you want to try and tackle it go to arboristsite.com and search 026 adjustable oiler. There are several posts about doing it and the parts list.

 

[quads]

Yep, you guys are right, both of my saws are 026 and not Pro. Or at least neither one of them say Pro on them. It's funny the one oils so much more than the other.

I downloaded the owners manual from Stihl a little while ago and it tells in there how to adjust the oiler, which way to turn the screw, etc. A few minutes ago I went out in the garage and studied both of them again. Turned them upside down and looked way down in that hole with the flashlight, and there is no screw adjustment to be seen either saw. So, I assume that neither one of my saws was made with the adjuster, but yet the cases/covers must be the same as what is used on the ones with an oiler adjustment.

The one saw that oils a lot does leave a few blobs, and/or a little puddle of oil on the bench. The other 026 that doesn't oil so much (a year or two newer), and does not leave any on the bench.

No big deal. I just thought that maybe I was missing something. I wanted to turn the rate down a little on the drooler if I could, but since I can't, I won't worry about it.

Thanks for the help!

 

[Gooserider]

Don't know how possible / practical it would be, but is there any way to put a restriction in the oil line so that it won't quite flow so much?

The other possible option, and again, I don't know if it applies, but my understanding is that the oiler is a sort of piston pump driven by a cam off the sprocket - if there is some way to either shorten the piston a tiny bit, or move it further from the cam, then that might lower the amount of oil delivered per stroke...

Gooserider

 

[quads]

Don't know how possible / practical it would be, but is there any way to put a restriction in the oil line so that it won't quite flow so much?

The other possible option, and again, I don't know if it applies, but my understanding is that the oiler is a sort of piston pump driven by a cam off the sprocket - if there is some way to either shorten the piston a tiny bit, or move it further from the cam, then that might lower the amount of oil delivered per stroke...

Gooserider

The oil appears to flow out of a tiny brass nipple pressed into the case. I was thinking maybe the nipple could be replaced with a different size, like a carb jet can. I might ask the Stihl dealer about it someday.

I once read something about the Stihl oilers being driving off the clutch with a wire linkage of some-sort. I couldn't see any of that on mine, then read somewhere else that the older 026 oiler is driven directly off the crankshaft. Which appears to be the way with mine. As far as I can tell, everything is completely enclosed in the case, around the crankshaft, under the clutch shoes.

 

[smokinj]

Don't know how possible / practical it would be, but is there any way to put a restriction in the oil line so that it won't quite flow so much?

The other possible option, and again, I don't know if it applies, but my understanding is that the oiler is a sort of piston pump driven by a cam off the sprocket - if there is some way to either shorten the piston a tiny bit, or move it further from the cam, then that might lower the amount of oil delivered per stroke...

Gooserider

The oil appears to flow out of a tiny brass nipple pressed into the case. I was thinking maybe the nipple could be replaced with a different size, like a carb jet can. I might ask the Stihl dealer about it someday.

I once read something about the Stihl oilers being driving off the clutch with a wire linkage of some-sort. I couldn't see any of that on mine, then read somewhere else that the older 026 oiler is driven directly off the crankshaft. Which appears to be the way with mine. As far as I can tell, everything is completely enclosed in the case, around the crankshaft, under the clutch shoes.

not sure on the 026 but the 260 run off the clutch so you can set them down without pumping oil

 

[kevin j]

do you have thinner oil in one? the volume pumped should be the same, but thinner oil will drain out of the system ( in the end past the pump) a bit more.
I am not sure, but think it is a fixed volume pump so any kind of jet or restriction would not work.

On AS, Bcorradi is sort of the 026 parts source. He has OEM P&C sets the smaller 44 mm I think, for cheap. He also has the parts to convert to a 260 pro adjustable oiler if you want that. It is adjustable, and oils from the clutch not the crankshaft, so it can sit idling without pumping oil. Other than that he says there isn'tmuch flunctional difference. Parts are $55. He had one set left this week. I was looking at the converson if I rb my 026. I don't know if it is an external installation or if the case has to be split or machined.

 

[quads]

Don't know how possible / practical it would be, but is there any way to put a restriction in the oil line so that it won't quite flow so much?

The other possible option, and again, I don't know if it applies, but my understanding is that the oiler is a sort of piston pump driven by a cam off the sprocket - if there is some way to either shorten the piston a tiny bit, or move it further from the cam, then that might lower the amount of oil delivered per stroke...

Gooserider

The oil appears to flow out of a tiny brass nipple pressed into the case. I was thinking maybe the nipple could be replaced with a different size, like a carb jet can. I might ask the Stihl dealer about it someday.

I once read something about the Stihl oilers being driving off the clutch with a wire linkage of some-sort. I couldn't see any of that on mine, then read somewhere else that the older 026 oiler is driven directly off the crankshaft. Which appears to be the way with mine. As far as I can tell, everything is completely enclosed in the case, around the crankshaft, under the clutch shoes.

not sure on the 026 but the 260 run off the clutch so you can set them down without pumping oil

Yep, that's what I heard about the newer 026/260. But, mine aren't that way. Even at idle they pump oil. Especially the one that drools, which is even older than the other one. At idle, I can watch the oil slowly bubble up through the chain links.

 

[smokinj]

Don't know how possible / practical it would be, but is there any way to put a restriction in the oil line so that it won't quite flow so much?

The other possible option, and again, I don't know if it applies, but my understanding is that the oiler is a sort of piston pump driven by a cam off the sprocket - if there is some way to either shorten the piston a tiny bit, or move it further from the cam, then that might lower the amount of oil delivered per stroke...

Gooserider

The oil appears to flow out of a tiny brass nipple pressed into the case. I was thinking maybe the nipple could be replaced with a different size, like a carb jet can. I might ask the Stihl dealer about it someday.

I once read something about the Stihl oilers being driving off the clutch with a wire linkage of some-sort. I couldn't see any of that on mine, then read somewhere else that the older 026 oiler is driven directly off the crankshaft. Which appears to be the way with mine. As far as I can tell, everything is completely enclosed in the case, around the crankshaft, under the clutch shoes.

not sure on the 026 but the 260 run off the clutch so you can set them down without pumping oil

Yep, that's what I heard about the newer 026/260. But, mine aren't that way. Even at idle they pump oil. Especially the one that drools, which is even older than the other one. At idle, I can watch the oil slowly bubble up through the chain links.

I would learn to live with it...lol

 

[quads]

do you have thinner oil in one? the volume pumped should be the same, but thinner oil will drain out of the system ( in the end past the pump) a bit more.
I am not sure, but think it is a fixed volume pump so any kind of jet or restriction would not work.

On AS, Bcorradi is sort of the 026 parts source. He has OEM P&C sets the smaller 44 mm I think, for cheap. He also has the parts to convert to a 260 pro adjustable oiler if you want that. It is adjustable, and oils from the clutch not the crankshaft, so it can sit idling without pumping oil. Other than that he says there isn'tmuch flunctional difference. Parts are $55. He had one set left this week. I was looking at the converson if I rb my 026. I don't know if it is an external installation or if the case has to be split or machined.

Hey! You might be on to something there! I never thought of that, because I have used the same kind of bar oil for a couple years now. But, the older saw hung on the wall for probably 3 years until yesterday. And I most likely had a different kind of bar oil in that one. Probably the Wal-mart brand which is a little thinner than the stuff I use nowadays. I did top the oil tank off with fresh before I started it yesterday, but there was still some in it from years ago. So, you could be right.

Although, it seems to me that one always did pump more oil anyway, but I may have used more of the thinner brand in it which just made it seem like it. Hopefully today I will get a chance to go out and cut awhile with it, if I get time and if the latest snowstorm hasn't left me with too much snow to get around in the woods.

 

[quads]

I would learn to live with it...lol

Ha! You're right. Only thing I worry about is running out of bar oil before gas and not noticing it. Especially when I'm cutting in the summer. I don't remember it ever running out, so as long as it isn't using any more oil than it used to, I should be good to go.

 

[smokinj]

I would learn to live with it...lol

Ha! You're right. Only thing I worry about is running out of bar oil before gas and not noticing it. Especially when I'm cutting in the summer. I don't remember it ever running out, so as long as it isn't using any more oil than it used to, I should be good to go.

I had that issue with a ms 180 but still never ran short of oil

 

[Kong]

The 026-Pro had both a compression release and an adjustable oiler. Straight 026 saws did not as far as I know.

At any rate, if yours has an adjustable oiler it will be found, or accessed, from the bottom of the saw. Flip the saw over and look closely at the bottom, a couple of inches back from the front of the saw body on the same side as the guidebar. There will be a little hole with markings around it. The markings show which way to turn the adjuster to increase or decrease the oil flow rate. You use a small straight-blade screwdriver to reach down into the hole and adjust the screw.

As for the adjuster screw falling out, if it did that the pump would cease to pump immediately. The pump works by way of a ground eccentric on the end of a shaft (driven by the clutch rotation) making a machined in part act as a piston and move a miniscule amount of oil with every revolution. However to do that it has to ride on a ramp that is machined into the end of the adjusting screw. So if the screw falls out (its held in place by a split-pin) the pump quits moving in and out (it will still spin) and oil will not flow.

In the end it is always difficult to imagine a saw that oils too much. While the pump itself is a pretty straight forward device that's pretty hard to break it could still dribble a lot of oil out the bottom if it came lose - and that seems to me to be a better chance of what's happening than anything else.

Try this. Remove the bar and chain. Break out your little torx socket and remove the little stainless steel plate that guides the chain, one screw between the bar studs holds it in place.

Next take a screwdriver and remove the clip that is holding your clutch on the driveshaft, just pop it off and then set it and the washer under it aside. Now lift off the clutch shell. Look at its bottom edge, see that little slot? Keep it in mind for when you put the saw back together. OK, under that bell-looking part you just took off you'll see the clutch itself. Notice that its got a machined part where it screws onto the crankshaft that will be happy to accept a 3/4" (19mm) deep-socket. Lock the engine so it can't turn and remove the clutch as a complete assembly by rotating your wrench clockwise - this is a left-handed-thread and it spins in the opposite direction from what you are used to - clockwise to loosen it, counterclockwise to tighten it.

OK, spin the clutch assembly off of the crankshaft and set it aside. Now, you are looking at the oil pump. See that bent wire thing sticking out the side? That is what drives it when the clutch is spinning. The pump itself is held down by two screws. I'd bet yours are lose. Put a daub of blue locktite on each one and then snug them back down - oh, they will require the same torx socket you used to remove the chain guide. Don't over-tighten them, they break easily.

Then screw your clutch back on, just get it good and hand tight. Because of its backwards threads and the direction the engine spins it will tighten itself as the saw runs After that put the bell-looking part of the clutch back on. Remember that slot? Well the little wire arm that drove the oil pump has to slip into that slot when you put it all back together. Its not difficult. Then put the rest of the saw back together. Oh, depending on which type of chain drive you have there may be a sprocket on the top of the clutch and there is also a caged bearing between the clutch and the crankshaft that slips in and out - you might want to replace it, they cost about $6 at your local Stihl dealer.

See how simple I made that sound? Well, I have to tell you something, its not much harder to do in person that it was to read those couple of paragraphs. Really, its that easy, go give it a try. There's hardly any chance at all you'll screw anything up - its really that easy. The worst you could do is lose a part so you'd have to take it back to your Stihl dealer in a box - but other than a little embarrassment it might actually save you a little money on shop time to bring it in as a basket case.

Oh, here's something else you could possibly find. Sometimes that caged bearing between the clutchf and the crankshaft fails, and when it does that bell looking part of the clutch can wobble. If it wobbles it will, or can, contact the oil pump body and wear a slice through it. Sometimes that slice will cut into the oil passageway in the pump. If that happens the pump might/could/will dribble oil out the bottom but put none on the chain. If that were the case you'd have to replace the pump - $20~30 on E-Bay, probably $75 from the dealer (just a guess).

 

[quads]

The 026-Pro had both a compression release and an adjustable oiler. Straight 026 saws did not as far as I know.

At any rate, if yours has an adjustable oiler it will be found, or accessed, from the bottom of the saw. Flip the saw over and look closely at the bottom, a couple of inches back from the front of the saw body on the same side as the guidebar. There will be a little hole with markings around it. The markings show which way to turn the adjuster to increase or decrease the oil flow rate. You use a small straight-blade screwdriver to reach down into the hole and adjust the screw.

As for the adjuster screw falling out, if it did that the pump would cease to pump immediately. The pump works by way of a ground eccentric on the end of a shaft (driven by the clutch rotation) making a machined in part act as a piston and move a miniscule amount of oil with every revolution. However to do that it has to ride on a ramp that is machined into the end of the adjusting screw. So if the screw falls out (its held in place by a split-pin) the pump quits moving in and out (it will still spin) and oil will not flow.

In the end it is always difficult to imagine a saw that oils too much. While the pump itself is a pretty straight forward device that's pretty hard to break it could still dribble a lot of oil out the bottom if it came lose - and that seems to me to be a better chance of what's happening than anything else.

Try this. Remove the bar and chain. Break out your little torx socket and remove the little stainless steel plate that guides the chain, one screw between the bar studs holds it in place.

Next take a screwdriver and remove the clip that is holding your clutch on the driveshaft, just pop it off and then set it and the washer under it aside. Now lift off the clutch shell. Look at its bottom edge, see that little slot? Keep it in mind for when you put the saw back together. OK, under that bell-looking part you just took off you'll see the clutch itself. Notice that its got a machined part where it screws onto the crankshaft that will be happy to accept a 3/4" (19mm) deep-socket. Lock the engine so it can't turn and remove the clutch as a complete assembly by rotating your wrench clockwise - this is a left-handed-thread and it spins in the opposite direction from what you are used to - clockwise to loosen it, counterclockwise to tighten it.

OK, spin the clutch assembly off of the crankshaft and set it aside. Now, you are looking at the oil pump. See that bent wire thing sticking out the side? That is what drives it when the clutch is spinning. The pump itself is held down by two screws. I'd bet yours are lose. Put a daub of blue locktite on each one and then snug them back down - oh, they will require the same torx socket you used to remove the chain guide. Don't over-tighten them, they break easily.

Then screw your clutch back on, just get it good and hand tight. Because of its backwards threads and the direction the engine spins it will tighten itself as the saw runs After that put the bell-looking part of the clutch back on. Remember that slot? Well the little wire arm that drove the oil pump has to slip into that slot when you put it all back together. Its not difficult. Then put the rest of the saw back together. Oh, depending on which type of chain drive you have there may be a sprocket on the top of the clutch and there is also a caged bearing between the clutch and the crankshaft that slips in and out - you might want to replace it, they cost about $6 at your local Stihl dealer.

See how simple I made that sound? Well, I have to tell you something, its not much harder to do in person that it was to read those couple of paragraphs. Really, its that easy, go give it a try. There's hardly any chance at all you'll screw anything up - its really that easy. The worst you could do is lose a part so you'd have to take it back to your Stihl dealer in a box - but other than a little embarrassment it might actually save you a little money on shop time to bring it in as a basket case.

Oh, here's something else you could possibly find. Sometimes that caged bearing between the clutchf and the crankshaft fails, and when it does that bell looking part of the clutch can wobble. If it wobbles it will, or can, contact the oil pump body and wear a slice through it. Sometimes that slice will cut into the oil passageway in the pump. If that happens the pump might/could/will dribble oil out the bottom but put none on the chain. If that were the case you'd have to replace the pump - $20~30 on E-Bay, probably $75 from the dealer (just a guess).

Wow, great post! Thank you. I'm heading out right now to cut with it for awhile, and I'll see how it goes. Both saws have the hole with the markings around it, but no screw up in there on either one. An empty hole.

 

[Kong]

The adjuster screw, if you have one, is a tricky little bugger to see. When you look into the hole on the bottom a lot of times you can't see it. If you have one there is a second little hole down inside the hole with the marks around it. The little hole is maybe 1/8" in diameter (and probably filled with mud or sawdust) and you have to get a little teeney screwdriver down in it to make the adjustment. Once in there its only about 1/4 turn for the full range of adjustment. Anyway it can be tricky to see at first.

So don't give up just yet, you still might have one - or not.

 

[quads]

Had it out today and it runs great! That $3 rubber impulse hose really did the trick. I should have diagnosed the problem years ago, but didn't. It's funny how that older 026 has so much more power and runs so much better than the newer one. I think if the newer one had all the carb adjustments, so I could lean it out just a hair, it would run much better.

It did not run out of oil. I didn't run it quite out of gas, but it still was pumping oil. I think it will be ok, even though it definitely pumps more oil than the other one. I looked it all over and the oil is coming out where it's supposed to be, and doesn't seem to be leaking anywhere that it shouldn't be. With the saw idling, and the chain not moving, I can watch the oil ooze up through the nearest links to the oiler. It pumps up out of the links slowly, like a heartbeat. I'll look again sometime at the hole in the bottom of the saw for the adjuster screw, but I took the clutch bell off and looked in there pretty close yesterday and could see no screw. Maybe they used the same case on it as they do on the Pro saw, even though this one has no adjustment.