Stihl MS 261 chain brake engages randomly

[MinnCC]

Anyone ever deal with a Stihl chainsaw where the chain brake will engage randomly in the middle of bucking cuts without touching the chain brake lever or doing anything that should engage the inertia brake? So far, we've cleaned out the levers and springs and put in some grease on pins, but it seems worse if anything. This isn't the only model in our fleet that has had this issue. A 201c was also engaging the chain brake randomly. Carving out the notch in the brake assembly seemed to help with that one at least temporarily, but I'm wondering if there is something we've missed so far.

Before I hear it: I really, truly don't need to hear about your opinions on Stihl. I have my own complaints, but this is the fleet that I have to maintain for work, and another brand is not an option.

Thanks in advance for any insight!

 

[meathog]

Had you worked on/taken apart the chain brake before?

 

[Tobystihl]

It may be caused by a weak spring in the brake catch coupled with a worn detent in the brake handle.

 

[JPCalifornia]

This is actually by design. The European Union has forced chainsaw manufacturers to install a “use limiter” on all new tree cutting equipment!

 

[Marley5]

I had one saw do that and my patients grew so thin that I removed the brake assembly.....no brakes
Still have that saw today after 12 years and have grown fond of it.
I don't start my saws with the brake engaged but not going to advise against it.

 

[trains]

It may be caused by a weak spring in the brake catch coupled with a worn detent in the brake handle.

Ive also come across this, and another cause can be too much grease/ oil lubrication on the cam assembly, causing it to easily engage as you describe, blow the area out with some air again, and just leave a light residue of lubricant on the assembly and see how that behaves, if it improves, then give it a clean with some degreaser and see how it behaves then.