ported 661 - muffler testing

[Moparmyway]

best way to tackle a 661 MM?

With a burr

 

[Redbull661]

IMO it depends on -

1) how much air is coming in.
2) jug...if it's stock or ported...and how it's ported.
3) thin or wide weave spark screens
4) baffle in or out

IMO these determine size of exhaust ports.

so for a basically stock 661 - just taking out the baffle and using a wider weave screen go a long way. The stock port is .625" diameter. I lost performance when I went larger than .88" diameter.


Even after all the testing I've done, I'm still testing muffler mods on the ported 661s. In other words it takes a lot of testing to find "ideal". In fact I was testing some more yesterday... lol

running tm2 with a diff mod 404 full comp 36".

 

[rogue60]

IMO it depends on -

1) how much air is coming in.
2) if it's stock or ported...and how it's ported.
3) thin or wide weave spark screens
4) baffle in or out

IMO these determine size of exhaust ports.

so for a basically stock 661 - just taking out the baffle and using a wider weave screen go a long way. The stock port is .625" diameter. I lost performance when I went larger than .88" diameter.


Even after all the testing I've done, I'm still testing muffler mods on the ported 661s. In other words it takes a lot of testing to find "ideal". In fact I was testing some more yesterday... lol

running tm2 with a diff mod 404 full comp 36".

What's that white stuff ash?
I took the hd2 filter crap thing off a stock 661 and did a heap of cuts with no filter was a notable difference in power way more than I have felt with a light muff mod on its own on a 661?!?. I prefer the older all flat surface Stihl filters whatever they where called they don't block up like the hd2 filters and breath, sure fines get through but not much different than the hd2 as far as fines getting through really go figure.
I've never seen sawdust fines do any harm to a saw with a thousand hrs or so on em yet? piston skirt wear yeah let's blame that on sawdust fines too funny ha.
Have you run that big filter thingy guys put on saws? you know the one looks like a big D? in ya face thingy are they really necessary? All I see is it getting in the way who wants that thing in ya face all day? lol, so many different types of cuts it would be in the way must be why you never see cutters in the bush use em? meh just thinking out loud.

 

[Moparmyway]

What's that white stuff ash?
I took the hd2 filter crap thing off a stock 661 and did a heap of cuts with no filter was a notable difference in power way more than I have felt with a light muff mod on its own on a 661?!?. I prefer the older all flat surface Stihl filters whatever they where called they don't block up like the hd2 filters and breath, sure fines get through but not much different than the hd2 as far as fines getting through really go figure.
I've never seen sawdust fines do any harm to a saw with a thousand hrs or so on em yet? piston skirt wear yeah let's blame that on sawdust fines too funny ha.
Have you run that big filter thingy guys put on saws? you know the one looks like a big D? in ya face thingy are they really necessary? All I see is it getting in the way who wants that thing in ya face all day? lol, so many different types of cuts it would be in the way must be why you never see cutters in the bush use em? meh just thinking out loud.

The MaxFlow for the 661 is a thing of beauty and it stops all fines from getting into the intake as well as flowing enough air to make you think that you're running without any filter

 

[CR500]

The MaxFlow for the 661 is a thing of beauty and it stops all fines from getting into the intake as well as flowing enough air to make you think that you're running without any filter View attachment 53346

Really is noticeable how the air flow is....some may say it is less.

I think it is noticeable in power.


Really happy I bought one, may end up getting the 064 kit even if it looks boxy

Sent from my non internal combustion device.

 

[Deets066]

Really is noticeable how the air flow is....some may say it is less.

I think it is noticeable in power.


Really happy I bought one, may end up getting the 064 kit even if it looks boxy

Sent from my non internal combustion device.

It don't look boxy if ya ditch the cover.

 

[blsnelling]

You can modify the stock filter cover to work with the MaxFlow.

 

[RI Chevy]

It don't look boxy if ya ditch the cover.

View attachment 53507

Love the muffler pipe!

 

[RI Chevy]

Thanks again for the testing Julian. I didn't notice, but are you still using the green foam filter?
That saw runs real good. And god bless you for cutting in what looked like darkness and snow for the good of us all.