The 2025 346xp Porting Thread

[oddsawz]

After repairing saws back to stock for 8 years I decided to offer up services to a couple of tree service friends. It became clear that they wanted a bit more out of their saws so I started the porting journey.

First up I had a go at a 346xp. I’ve had a personal one for several years and it always blew me away. I had never run anything with work done.

Got some good info from a lot of threads on here and from various YouTubers. I just didn’t want to bump the old threads I was hoping everyone could share their experience in a newer thread for those late to the 346 party

I have just finished the build and here is what has been done:

-Machined squish band and base 0.050
-Matched cylinder to crankcase
-Widened exhaust port piston side
-Matched exhaust to gasket, muffler side
-Smoothed entry on lower transfers
-Knife edged lower transfer divider
-plugged decomp hole

Exhaust port vs stock

Final numbers:
0.019 squish
105 exhaust
127 transfer - 22 blow down
78 intake

Other parts:
346xp intake boot
357/359 carb mount
HDA 199 carb
357/359 air filter/elbow
Cylinder cover without primer hole



Modifications:
-Opened up carb base floor to fit 357/359 switches.
-Ground a few mm from crankcase where intake partition sits.
-Gutted fuel vent in tank, but ended up using an echo style vent on the end of the vent hose
-Muffler mod, used a dukes wide deflector




It runs and screams but I haven’t really got to test it yet because of the heat. I made three cookie cuts so far and it feels pretty strong. Hoping to get some video soon and put it up against another stock 346xp for comparison.

I have a few more to work on and would maybe like to decrease the blowdown on the next one.

All feedback/advice/hate is appreciated

 

[oddsawz]

Got a few more to work on too

 

[huskihl]

I’d try a lower exhaust and much higher transfers

 

[huskihl]

Stock vs xs ported. Both have 357 carb