First time porting

[ken4nedy]

I'm thinking about doing some porting on my Stihl MS 261 and I have to admit, I've never done anything like this before. I've watched a few videos and read some guides, but actually opening up the case and messing with the ports feels like a whole different level. I'm trying to get a sense of what I'll need afterward. Are there adjustments I should plan on, like carb tuning, clutch work, or timing checks? I want to make sure I don't just get a better ported saw that won't run right because I missed something basic

 

[JJoe_257]

The 261 is a great saw to learn on! And yes, you'll absolutely need to do some carb tuning after you port it.
You'll be moving a lot more air, so the stock settings will be too lean.
Plan on adjusting the high-speed screw afterward to get it dialed in.
You don't need to mess with the clutch or timing since the timing on these is fixed anyway..
Just take your time with the port work, clean everything meticulously, and be patient with the carb tuning!

 

[Vorhi-heesy1985]

Yes, you’ll need to richen the carb after porting, but don’t overlook the muffler since opening the ports without matching exhaust flow can choke gains and make tuning harder. Did you plan on doing a muffler mod alongside the port work or are you keeping the stock can for now?

 

[Cuttingranger]

Hey, after you put things back together, make sure to check the compression. A big change there can mess with how it idles and starts up. Also, if you have new rings or cleaned up the cylinder wall, tuning it should be way easier.