Stihl ms290 exhaust

[Martin]

OK I have had a search but not been able to find any info so hoping someone may be able to point me in the right direction. I have seen people mention that they do modifications on exhaust to get more power from there saws, what do said modifications involve as I have just bought a stihl ms290, also can I do anything to stihl ms 180?

 

[RI Chevy]

Remove those 3 bolts and drill out a few holes behind that metal cover as well. Make sure you remove all the metal filings before remounting to your saw.
Be sure to retune the saw as soon as you are done. Nothing really special, just open up the area a little more and allow the saw to breathe better.

 

[RI Chevy]

 

[RI Chevy]

These were older photos that I took when I originally nodded the muffler. I have since drilled one more hole next to the one I already drilled. I went slowly and ran the saw to see if it made any difference. it definitely runs better more open.

 

[greendohn]

These were older photos that I took when I originally nodded the muffler. I have since drilled one more hole next to the one I already drilled. I went slowly and ran the saw to see if it made any difference. it definitely runs better more open.

Was re-tuning the carb needed after opening the muffler on your 290?
I would think the top end would need a little more fuel after opening the muffler?

 

[RI Chevy]

Oh yeah. Had to retune immediately.

 

[Martin]

Yks ld that's great now I know what to do

 

[Martin]

The last message meant to say "thanks that's great now I know what to do" got to love predicted txt it thinks it knows what you want to type.

 

[RI Chevy]

Lol. No problem. Good luck

 

[Cut4fun]

Most gains I have seen from a MM has been on the 290 so far 23%. Most 18%-23%

I put 2 holes in center, 2 above and 2 below. Have done 3 above and below on the 23% one.
I just open the deflector exit further. Never drilled holes in the front of deflector.

30mins to do and carb retune.