These bark boxes ?

[Nighthunter]

What's your opinion on them, thinking of comparing 1 of these to my muffler mod on my 462, anyone running these

 

[stranter]

Guy I work with has one on his 462. It’s loud enough to make your ears bleed. No idea if it’s any better than just a normal muff mod though.
I’d be interested to see if it’s any quicker

 

[jacob j.]

Several of the professional timber fallers here use them. I'm not sure that they're worth the expense for the average user, but for the Pro fallers they are, since
they have to switch over to a non-modified muffler when working during the fire season or at any time on federal government lands.

They can just swap covers out and be done with it.

 

[BonScott46]

Several of the professional timber fallers here use them. I'm not sure that they're worth the expense for the average user, but for the Pro fallers they are, since
they have to switch over to a non-modified muffler when working during the fire season or at any time on federal government lands.

They can just swap covers out and be done with it.

Are they any better than a factory style dual port cover on an 1122/1128? Can guys run the screened dual port covers during fire season?

 

[jacob j.]

Are they any better than a factory style dual port cover on an 1122/1128? Can guys run the screened dual port covers during fire season?

I don't know that they're any better than Stihl's own dual-port muffler covers, of course the older covers won't fit the new mufflers. On federal lands, you're not allowed to have any modified
components on a chainsaw, even port work inside the cylinder. If you're suspected of starting a fire while working on a contract, they take all of your equipment and send it to San Dimas or
Missoula for inspection/evaluation. If anything is found to be modified, you can be held liable for all of the suppression costs of the fire. Of course, some of the local units aren't enforcing that
requirement strictly. It's pretty rare for a contractor to start a fire and then be held liable. It's only happened three times that I know for sure that could be verified.

 

[ManiacalMark]

I know someone who did their own test on a stock 661 and saw 7% gain. Is it worth $75+ shipping? I don’t know but I know they’re loud.

 

[kneedeepinsaws]

Several of the professional timber fallers here use them. I'm not sure that they're worth the expense for the average user, but for the Pro fallers they are, since
they have to switch over to a non-modified muffler when working during the fire season or at any time on federal government lands.

They can just swap covers out and be done with it.

That is a really neat idea!! Never heard of that before

 

[Wonkydonkey]

Didn’t one of these get tested in the dyno thread ? @Red97 . Iirc, they aren’t worth the money....
but your circumstances may dictate otherwise

edit,,, a saw was tested then a bark box fitted in the thread and tested again..

 

[Red97]

Didn’t one of these get tested in the dyno thread ? @Red97 . Iirc, they aren’t worth the money....
but your circumstances may dictate otherwise

edit,,, a saw was tested then a bark box fitted in the thread and tested again..

7% ish gain on the 500i I didn't think it was any louder than most any other muffler mod.

 

[ManiacalMark]

7% ish gain on the 500i I didn't think it was any louder than most any other muffler mod.

There’s more to be had if you bought one, chopped half the deflector off and got rid of the bottleneck in it.

 

[Lightning Performance]

There’s more to be had if you bought one, chopped half the deflector off and got rid of the bottleneck in it.

Pics?

 

[ManiacalMark]

No pics, just stating what should be done. Those covers hold a lot of exhaust and heat back. Get it out as fast as possible

 

[Moparmyway]

There’s more to be had if you bought one, chopped half the deflector off and got rid of the bottleneck in it.

What do you mean ?

 

[Moparmyway]

No pics, just stating what should be done. Those covers hold a lot of exhaust and heat back. Get it out as fast as possible

Please elaborate

 

[ManiacalMark]

The cover is wide open inside until the very end there is a ramp up welded inside so the exhaust gases don’t blow right on the crankcase. So to me, that’s a bottleneck.

 

[Moparmyway]

The cover is wide open inside until the very end there is a ramp up welded inside so the exhaust gases don’t blow right on the crankcase. So to me, that’s a bottleneck.

On the MS500i ?

 

[ManiacalMark]

On the MS500i ?

All of them are made the same. I think my point I’m trying to get out of my head and onto the keyboard is maybe there’s extra heat and back pressure from this cover vs OEM? I’m not trying to get something going I’m just curious if I’m the only one who thinks this is possible.

 

[Moparmyway]

Welp, the 500i & most Stihls have removable front covers, with a pto side exhaust discharge. The bottleneck isn’t in the cover, it’s the pathway out.

Adding tubes/pipes to the front cover will help get rid of back pressure and heat. Even on the Stihls that don’t have a removable front cover, (they’re not all made the same) adding like shown below helps in more than one way. OEM or AM, the cover is NOT the problem.

 

[ManiacalMark]

I didn’t say that cover was a “problem” at all. I’ve just had the thought in my head “would it be better if it had a shorter deflector on the cover?”.

 

[Moparmyway]

Those covers hold a lot of exhaust and heat back.

The cover is wide open inside until the very end there is a ramp up welded inside so the exhaust gases don’t blow right on the crankcase. So to me, that’s a bottleneck.

there’s extra heat and back pressure from this cover vs OEM?

I didn’t say that cover was a “problem”.

Gotcha, my mistake