Stihl 391 muffler mod

[Parmstrong191]

I just did a muffler mod on my 391, carb tuned in and all. Currently running 25" bar with full skip chain, wondering if i could bump it up to 28" or possibly even 30"-32". 28" sounds more reasonable to me but looking for other(s) opinions!

[sawguy21]

Welcome! 28" probably the practical limit, even with the muffler mod the 391 won't produce enough power to comfortably handle more than that.