Sat in a guys garage for a while. Didn't want to deal with it. I messed with the switch a little. dumped the gas and put fresh gas in. It fires up. Fuel line is in real bad shape. Surprised it fired up. So replacing that. Also replacing the air filter which looks terrible. I want to convert it to .325 chain, as my 261 is set up for that. I have a parts 026 set up for .325. Can I swap everything over or will the sprocket sizes be different? I've never done anything like that.
picked up an 034
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Change the fuel filter as well go OEM for line and filter run some Seafoam in your mix
I mix 32:1 for all my saws vintage and modern
Sprockets could be different size as there were a couple different clutch drums on those saws. There was a small inside diameter sprocket for some of them and a large inside diameter one.
Or you may have spur drives on them.
I mix 32:1 for all my saws vintage and modern
Sprockets could be different size as there were a couple different clutch drums on those saws. There was a small inside diameter sprocket for some of them and a large inside diameter one.
Or you may have spur drives on them.
Rim sprockets come in three bore sizes:
Mini = 5/8" ID
Small = 3/4" ID
Standard = 7/8" ID
Rim sprockets are available in either 3/8" or .325" pitch (as well as some other chain pitches). You'll need to switch to a .325" sprocket. Unless you have a solid nose bar, you'll need to change the bar as well, so the sprocket in the tip matches your chain pitch.
There is also a spur style sprocket - which has what looks like a gear with big teeth as part of the clutch drum.
The bar for an 026 should also fit an 034. I don't believe the sprocket will interchange. If I'm not mistaken, the 034 takes a standard size. The 026 and 261 take a mini. (You should verify this before ordering, as I am not 100% certain.) Probably best to replace the sprocket anyway. They are a wear item, and many homeowner/landowner users run them far longer than they should.
Mini = 5/8" ID
Small = 3/4" ID
Standard = 7/8" ID
Rim sprockets are available in either 3/8" or .325" pitch (as well as some other chain pitches). You'll need to switch to a .325" sprocket. Unless you have a solid nose bar, you'll need to change the bar as well, so the sprocket in the tip matches your chain pitch.
There is also a spur style sprocket - which has what looks like a gear with big teeth as part of the clutch drum.
The bar for an 026 should also fit an 034. I don't believe the sprocket will interchange. If I'm not mistaken, the 034 takes a standard size. The 026 and 261 take a mini. (You should verify this before ordering, as I am not 100% certain.) Probably best to replace the sprocket anyway. They are a wear item, and many homeowner/landowner users run them far longer than they should.
I didn't get to check yesterday. I did google it and I didn't see the 261 and 034 as compatible. I also have a parts 361 but that's also set for 3/8. I want to build it someday.
I found the same bar described as fitting both the 034 and 261 on Baileys.
Try scrolling down and clicking on the "Fitment" link on this page.
It mentions 034 and 261. If you read across a bit further, you'll also see it mentions 026. So the bar mount is the same.
I'm pretty sure the sprocket has a different bore size for the 034 vs the 026/261, but you should verify that.
Inspected it tonight. They are different sizes. Any idea how the chain tensioner works on this saw? Is it missing a piece? Theres no where to loosen/tighten. Also would you clean out this exhaust?
![[Hearth.com] picked up an 034](https://www.hearth.com/talk/attachments/20260409_182824-webp.347362/ "[Hearth.com] picked up an 034")
![[Hearth.com] picked up an 034](https://www.hearth.com/talk/attachments/20260409_182850-webp.347363/ "[Hearth.com] picked up an 034")
![[Hearth.com] picked up an 034](https://www.hearth.com/talk/attachments/20260409_182709-webp.347364/ "[Hearth.com] picked up an 034")
The tensioner screw should be accessed from the front of the saw, just to the outboard side of the felling dogs. It's basically the head of the bolt that the tensioning pin rides on.
You have what is known a a spur sprocket. It's part of the clutch drum. If you want to change from 3/8" pitch to .325" pitch, you'll need to replace that clutch drum with something compatible with .325 pitch. You might have two choices: either get a .325 spur sprocket compatible with your saw, or replace the clutch drum with one that accepts replaceable rim sprockets. In my opinion, the latter is a much better choice, if it's available to fit your saw. Rim sprockets are much easier to replace when worn, and onece the proper clutch drum is installed, it's a simple matter to swap back and forth between a .325 and a 3/8" rim sprocket.
On the upside, if you decide to go through with this: your existing spur sprocket is worn well past the point where it should be replaced anyway.
I've attached a PDF I made some years ago showing the different sprocket styles and sizes you may find helpful if you are not already familiar with them.
You have what is known a a spur sprocket. It's part of the clutch drum. If you want to change from 3/8" pitch to .325" pitch, you'll need to replace that clutch drum with something compatible with .325 pitch. You might have two choices: either get a .325 spur sprocket compatible with your saw, or replace the clutch drum with one that accepts replaceable rim sprockets. In my opinion, the latter is a much better choice, if it's available to fit your saw. Rim sprockets are much easier to replace when worn, and onece the proper clutch drum is installed, it's a simple matter to swap back and forth between a .325 and a 3/8" rim sprocket.
On the upside, if you decide to go through with this: your existing spur sprocket is worn well past the point where it should be replaced anyway.
I've attached a PDF I made some years ago showing the different sprocket styles and sizes you may find helpful if you are not already familiar with them.
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Piston looks great
I wouldn't worry about the exhaust other than making the muffler hole as big as you can behind the removable screen, then re-tune the saw. Which you should do anyway
I wouldn't worry about the exhaust other than making the muffler hole as big as you can behind the removable screen, then re-tune the saw. Which you should do anyway
Thanks. I'll check it out once I get the new fuel line and air filter in the weekend. So cutting it out the size of the screen is fine? I did it on an old 290 I had but I didn't open it that big.
Yes it makes it breath easier
Up here nobody checks for spark screens, so mine are removed and much bigger holes
So to stay compliant if it is an issue you will want the screen to cover the enlarged hole.
And most important re-tune.
Up here nobody checks for spark screens, so mine are removed and much bigger holes
So to stay compliant if it is an issue you will want the screen to cover the enlarged hole.
And most important re-tune.
Thanks. I'll do that once I get the new fuel line on. I'm not the best at tuning but I'll watch a few videos again.
Once you get the ear for tuning then you have it...
I tune mine for the cutting season. Which can vary a lot here. +90F summers to -40F winters.
I tune mine for the cutting season. Which can vary a lot here. +90F summers to -40F winters.
I'd recommend having a plan for making sure it's tuned right before you do the muffler modification. If you are not comfortable/experienced at doing it already, find someone who is to help you out and give some pointers so you can learn in the process. If your saw is tuned correctly now, and you open up the muffler without retuning, you will likely be running lean, which is a good way to burn up a saw.
Here is one good video on tuning a chainsaw. It relates to saws before auto-tune and rev-limited ignition coils became popular:
How to Tune a Chainsaw
the tune on a manually tuned chainsaw should always be re tuned for weather conditions
This is a saw he just picked up so it needs to be tuned before you use it regardless.
Re-tuning makes no difference if it's stock of Muff Modded it has to be done before you use the saw
Who knows the saw may have an issue the new owner knows nothing about, and he goes and uses it and burns it down because it wasn't tuned.
If you really want to go after some more power do a base gasket delete
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