Eratic idle on Stihl 026

[jakethesnake]

Go figure! Went out today to cut some wedding cookies and grabbed the 026 to see if it would run. Started it up and it went right to a nice idle and stayed there (cold). Thought, "why not try?" so I took the critter to the wood yard and started cutting pieces off firewood length logs. Deliberately let the saw idle for longer periods of time than I ever do in "real life". It worked perfectly. I needed to hunt for more suitable rounds and instead of shutting the saw off, I just left it there loping along. Got back and started cutting again. Shut saw off, restart, idled fine. No issues whatsoever. My present theory is that there was crud in the carb but sitting with fuel in it dissolved the gunk and now the carb is clean again. Not sure if the problem will crop up again but for now the saw and its owner are happy. If it acts up again in the future, I'll continue the saga in this thread.

I'd be willing to guess you're correct there. I had a family members saw do the same thing. I too let it set a few days or week with new fuel in it. All the sudden the saw ran perfect again.
I blamed it on varnish from crappy old stale fuel left in there. Figured the new fuel to have dissolved the issue I wouldn't over think this one

 

[RD35]

Wow, this is a cool discussion. I, too, had recently worked on an MS31o that had been straight gassed some time back. After installing a new engine, I fired it up and was not happy with the way it ran. Pulled the carb, disassembled, cleaned, reassembled, and installed it. Ran better, but idled weird and died. Lucky for me I was out of time that evening and let it sit overnight. Next evening I fired it up and it ran, idled, revved, etc. just fine. Made a couple of teaks to H and L and it was ready to go. It always bothered me that it acted funny when I first ran it after the carb work. Now I think I know what happened. I think I will soak all carbs from now on for 24 hours just to be sure all the varnish is dissolved.

 

[FergusonTO35]

I sure hope my 024 fixes itself after sitting overnight with fresh fuel in it. Making very slow progress, have gone from basket case untouched for years to starts and runs but won't idle over the past few weeks.

Bilge Rat, how old are those Wild Things and what models are they?