Opening up the muffler: How much is too much?

[Mountainman]

I have two 026 mufflers I need to open up a bit. These will be my first. It appears that some say that we should shoot for 80% of the exhaust port area. Others have said to go for broke and open it up a lot. I am inclined to believe the 80% crowd, but would like to know for sure. So what say you: 80% or more?

Thanks in advance

 

[Justin Taylor]

I have two 026 mufflers I need to open up a bit. These will be my first. It appears that some say that we should shoot for 80% of the exhaust port area. Others have said to go for broke and open it up a lot. I am inclined to believe the 80% crowd, but would like to know for sure. So what say you: 80% or more?

Thanks in advance

%80 is the max for me I would start with 65%and go up from there

 

[user 122190]

Leave it as it is. For most here, noise is power, so cut without earplugs and you will achieve the same with no potential downside to the saw.

 

[Ax-man]

80 % is a good number . After that your just making noise and could defeat the purpose of the muffler mod and could lose power by having too much air flow out of the muffler upsetting the new charge entering the cylinder and losing some of the scavenging effect to keep the new charge from going back into the cylinder when the piston closes the exhaust. I'll probably get nailed to the cross for that statement but this is just my way of thinking when it comes to these muffler mods.

 

[motor head]

They look and sound cool with that wide open MM.But I think you sacrifice power going that route.I leave the baffles alone and only open the outside of the muffler.Ive measured a lot of baffles and have them to be around 80 percent so I don’t mess with them .The outlet is usually where the restriction is.

 

[Ax-man]

That is pretty much the way I do it.

 

[sunfish]

In this case, less is more. But if the saw is ported it could be different.