026 carb issue

[poorboypaul]

Have an 026. Not an AV, but not the pro because it doesn't have a decomp. Problem is the carb mix needles aren't staying adjusted. Adjustment lasts about 5 minutes and they've moved and it runs like crap. Just wondering if I can get new springs or if the plastic piece the springs screw into has shrunk with age. The springs are touching each other on the bottom side, so I don't know if this is allowing them to not work properly or not. Didn't find anything in the archives on this type of issue. Just don't want to have to purchase a new carb. Thanks in advance for any info!

 

[z71mike]

Did you actually verify that the screws are moving by counting turns? Cause that's rare. It's more likely that the screws aren't moving, but rather you can't hold a tune because of an air leak somewhere.

 

[poorboypaul]

The mix needles are turning. I checked their adjustment before and after. After I disassembled the saw and adjusted them with the carb out, at least one of them has no resistance on it and turns freely.

 

[z71mike]

Remove needle. Stretch spring. Reinstall.

 

[hotshot]

Not sure if you have the space, but I've seen the RC airplane & boat guys place a stub of 3/8" auto vacuum hose and a hog ring type hose clamp over them, basically locking the two screws together.

 

[Rockjock]

Remove needle. Stretch spring. Reinstall.

a little of the low-med strength loctite will hold them as well. It will only set after a few mins.

 

[Big_Wood]

i'm gonna go ahead and believe you that the springs are weak and i agree with mike about stretching the springs but please be aware that the 026 along with a few other stihls have a problematic seal. for the 026 and 036 it is the flywheel side. some like the 200 have the same seal on both sides. it sucks. i just replace seals in most saws i receive. take a seal out of even a 10yr old saw and compare it to a new seal. you will find the new seal to be way softer. even though that old seal may still be sealing, it will let go one day.