Stihl 261CM suddenly stall-prone

[fc1]

I've had my Stihl 261C for about 3.5 years and operator-errors aside it's always been totally appliance-like in its function. Kept it sharp and in fluids and it worked great, consistently.
Until recently...
Now from cold it will fire and run in "Start" just fine, but unless I'm careful to run it (cut) immediately off "Start" it will usually stall and refuse to refire for an extended period.
Spark arrestor is clean. Air filter is original but not visibly dirty in a way that looks to have an impact. I wire-brushed and regapped the plug (and confirmed spark).
I got fresh gas and made fresh premix. All of which made zero difference.
I know both the coil and fuel solenoids have caused problems; does my issue sound related? Time for dealer visit? Should still be under warranty...

 

[xyz123]

WAG. Seen this on others. Sounds like dirty solenoid.

They have a updated ones and fuel filter for alot of stihl's now.

Only sure way to know is pay the piper to hook it up at dealer.
Or take the chance and replace the 2 parts yourself and save the $100 a hour they going to charge ya. But if not it cost ya anyways.

 

[dodge man]

I know the spark plug looked ok but I’d stick a new on in it. I had a spark plug fail and the saw acted like you described. That’s probably not the issue but cheap to replace.

 

[xyz123]

Yes do that first put new plug it it before jumping further. I have had new plugs from ngk even be bad right out of the box. So just make sure you use a known good plug.

Here is what the new fuel filter looks like. If you have a white one it lets double the fine size by.

 

[Dan Hunter]

I vote bad plug as well. 2-strokes are firing twice as often and run at what would be crazy RPMs in a 4-stroke. They just don't last as long.

Just last week, my leaf blower began to struggle. It'd start but not want to build RPMs. The plug had great color but was old. A fresh plug solved it.

 

[ericm979]

New plug and the correct fuel filter (Mtronic needs a better one than the usual one for carbs).

Then try the Mtronic reset procedure. It should be in the manual. There's two different ones depending on the generation of the Mtronic.

 

[dodge man]

The plug I had go bad the center electrode could be pulled out it was so loose, that sucker is long.

 

[fc1]

Y'all are awesome. I have to admit I headed to AutoZone this am with the idea that while it would be *nice* if the plug fixed it, but...

The improvement in the saw was so obvious and immediate that I swapped plug in my 2-stroke Kombi as well. What do you know- the start/idle/restart behavior on that improved too!

Sincere appreciation for the input.

 

[Hay Dude]

My 1 year old heavily used 261C began the same issue yesterday. It ran fine, then it would start and idle, but as soon as you’d try to tach it up, it would stall.

I dumped out the fuel tank and tried some newer fuel from another fuel jug and it ran again.

However the other saws ran fine on the previous fuel so I’m suspicious its something else.

 

[fc1]

Spark plug worked for me!