Tuning a Stihl MS260 Pro with 18" 3/8 bar

[Mr. Piste]

Hey, everyone!

I just put a 18" 3/8 Tsumura bar on my Stihl MS260 Pro, which I just recently gave new piston rings and a carb rebuild. I'm in the midst of tuning it, and I have to admit, fixed-jet carbs are not the best. So my first question is should I install a fully-adjustable carb if I'm going to run this B&C setup? And should the saw be set to factory settings, or should it be set a bit richer? As it is now, it's running at a max of 11,500RPMs, which I know is way too low for that saw normally, but I'm not sure what it should be in this situation. I should also add that this is one of the first saws that I've ever tuned, so all of this is fairly new to me

What do you guys think?

 

[porsche965]

A bit rich will never get you into trouble with a new saw for awhile.

 

[Frogfarmer]

An 18" 3/8 bar will keep the engine loaded while in the cut so the duty cycle will be fairly high. This will create heat and a lean tune will have even more heat. Watch several tuning vids on the Tube and get an idea for what four stroking sounds like compared to when it cleans up in the cut with a proper tune. Leave it fat/rich until you fully understand the sounds and can determine exactly when it makes the transition. You do need to invest in a fully adjustable carb if you want the best results.