Makita 7000 muffler mod

[Colonel 428]

So I have done a muffler mod on my 7900. Two specific questions please:
1) I ground the bracket off flush (leaving the bracket and 2 holes of course) coming in to the muffler. I left the back part of the baffle that goes into the cylinder. Should I remove this as well?
2) I opened up the existing exhaust port as much as I could - turned the round hole into a square and replaced the spark screen. Do I need to add an additional exhaust port on the opposite side of the muffler about the same size?

 

[Colonel 428]

Sorry to not include pictures but I've got it back together and don't really want to split the muffler again

 

[Wilhelm]

Humble Dolmar/Makita 64xx/73xx/79xx "bird cage" muffler mod.
https://opeforum.com/threads/show-off-your-muffler-mods.6898/page-19#post-536316

Humble Dolmar/Makita 64xx/73xx/79xx SLR muffler mod.
https://opeforum.com/threads/show-off-your-muffler-mods.6898/page-47#post-675717
https://opeforum.com/threads/show-off-your-muffler-mods.6898/page-48#post-675859
https://opeforum.com/threads/show-off-your-muffler-mods.6898/page-48#post-675860

In regards to Your questions:
1) Yes, cut the tube going into the cylinder off
2) Unless the saw is ported I don't think a second outlet is required.

 

[Ford3000]

You will need to re tune the carb, and your going to but more fuel now,
but I presume you needed the extra grunt.

 

[Wilhelm]

The SLR mufflers are choked too much, those need to be modded.

I disliked my PS-7310 with the SLR in place, she was also gutless.
Once the SLR tube was removed she pulls my 36" B&C setup just as well as my PS-7900, one of my favorite saws now.

Placing multiple huge holes into the muffler is not really necessary, not on these saws anyway.

 

[Colonel 428]

Thanks Wilhelm for all your advice and guidance.

 

[Wilhelm]

You are very welcome!