Stihl 2-mix strato vs Husky/Poulan strato

[Dellirium]

It says stratified layer of gasses essentially in the text. The picture/ 10 second animation shows the kind of engine with the long transfer tunnels. Other ways of getting a stratified exhaust/air/mix probably count too as long as it is a Stihl but I am left to assume that.

You are right, they took more than 1 approach to use the strato technology, but currently they advertise the 2Mix as being the way to go. As previous stated i’m still skeptical about it and i want to see if it’s gonna be succesfully implemented on bigger, meaner, powerful products

 

[KostasVolos]

You are right, they took more than 1 approach to use the strato technology, but currently they advertise the 2Mix as being the way to go. As previous stated i’m still skeptical about it and i want to see if it’s gonna be succesfully implemented on bigger, meaner, powerful products

The pro grade MS261 C-M , MS400 C-M , MS462 C-M ,MS500i
and MS661 C-M being currently sold here in Greece ,they all have 2-mix engines .

 

[Dellirium]

The pro grade MS261 C-M , MS400 C-M , MS462 C-M ,MS500i
and MS661 C-M being currently sold here in Greece ,they all have 2-mix engines .

Well it seems i’m misinformed. Basically due to not having one of those for a repair, but still i should have read more before making that statement. Thanks for the heads up, i’m gonna check their schematics in detail later, i’m curious about differences between old and new style for some of them

 

[Franny K]

The pro grade MS261 C-M , MS400 C-M , MS462 C-M ,MS500i
and MS661 C-M being currently sold here in Greece ,they all have 2-mix engines .

Take the MS500i, That has the long transfer tunnels and fuel injection. What makes it 2-mix? no air only passageways.

 

[KostasVolos]

Well it seems i’m misinformed. Basically due to not having one of those for a repair, but still i should have read more before making that statement. Thanks for the heads up, i’m gonna check their schematics in detail later, i’m curious about differences between old and new style for some of them

I can testify a personal experience,regarding the MS180 2-mix .
I had a conversation recently with
a Stihl technician and asked him about his opinion regarding the "ordinary" MS180 versus it's 2-mix version .He said that the older MS180 had wider torque band and higher fuel consumption than the new strato MS-180.
Well,I revisited him with one of my recently modded MS180 2-mix
( drilled air filter box insert ,muffler mod at 85% of port and stock carb C1Q S286D with 0.45 main jet & metering compensation disabled ) .He tried the saw and he responded that my
modded saw had truly a wider torque band than stock ones and
had enough power to compete with a stock MS211 .He noted that the saw must be the most powerful MS180 2-mix he ever got hold of .He was pretty amazed .

I think no other mod can be done,since it has a rather small cylinder to allow porting and advancing timing ( flywheel key filing ) is not really needed since it's electronic ignition does have
variable timing .

 

[KostasVolos]

Take the MS500i, That has the long transfer tunnels and fuel injection. What makes it 2-mix? no air only passageways.

The MS500i 2-mix sold here does have air only passage ways ,at least on it's intake boot.
Most probably the US model is
different than the EU one.

 

[Franny K]

I can testify a personal experience,regarding the MS180 2-mix .

This is confusing. I thought the models that end in 1 have the advanced engine and the ones ending in 0 the earlier version.

per Stihl USA site, neither use the term 2-mix
180 The MS 180 chainsaw gets back to basics
181 A chainsaw with reduced-emission engine technology,

As to the 500i just from I have remembered from internet sites such as this one it does not have pockets in the side of the piston. Enough combustion by-products get pushed into the transfer tunnels which sufficiently minimizes combustion remains mixing with fresh charge.

 

[cscltd]

I believe they call the EU version of ms170/180 2mix as to not confuse them with the older non strato version if a person is looking for parts- they should have called them a different model- but Hans Peter Stihl decides on the model numbers or did for a long time.
the ms170 ms180 was suppose to be retired when ms171 ms181 came out- but no one liked them

 

[KostasVolos]

This is confusing. I thought the models that end in 1 have the advanced engine and the ones ending in 0 the earlier version.

per Stihl USA site, neither use the term 2-mix
180 The MS 180 chainsaw gets back to basics
181 A chainsaw with reduced-emission engine technology,

As to the 500i just from I have remembered from internet sites such as this one it does not have pockets in the side of the piston. Enough combustion by-products get pushed into the transfer tunnels which sufficiently minimizes combustion remains mixing with fresh charge.

Here in EU the non strato MS170/180 were sold before the
EU Emissions Directive Stage II came into play.Which is far more
strict than the US EPA standards.
I think that the Stihl 2-mix engines are used at Stihl products for the EU market .

Here in Greece I can find the older non-strato MS170/180 chainsaws ,but only as used saws,while as brand new the MS170/180 2-mix and the MS171/181 are currently available for sale from Stihl .

 

[KostasVolos]

I believe they call the EU version of ms170/180 2mix as to not confuse them with the older non strato version if a person is looking for parts- they should have called them a different model- but Hans Peter Stihl decides on the model numbers or did for a long time.
the ms170 ms180 was suppose to be retired when ms171 ms181 came out- but no one liked them

Yeap !
The MS170/180 2-mix have most of their engine parts being different than the older non strato MS170/180:
Cylinder,piston ,carburetor,air filter box ,intake boot ,connecting rod ,main bearings and their seals,spark plug and ignition module being some examples.

 

[huskihl]

The pro grade MS261 C-M , MS400 C-M , MS462 C-M ,MS500i
and MS661 C-M being currently sold here in Greece ,they all have 2-mix engines .

The 500 and 661 aren’t. They’re still old school. Carbon credit type thing like Ben mentioned earlier

 

[KostasVolos]

The 500 and 661 aren’t. They’re still old school. Carbon credit type thing like Ben mentioned earlier

These two links are from Stihl UK
( same EU Emissions Directive Stage II with rest of EU ) .

https://m.stihl.co.uk/STIHL-Product...-work/287735-130/MS-500i-Petrol-Chainsaw.aspx
https://m.stihl.co.uk/STIHL-Product...ork/22284-130/MS-661-C-M-Petrol-Chainsaw.aspx
Check out the "features" tab ,on
both .

"1-in-4 channel technology. The economical STIHL 2-MIX engine with 1-in-4channel technology features a high torque over a wide speed range. The chainsaw provides fuel savings of up to 20% compared to STIHL two-stroke engines in the same performance class without 2-MIX technology. Exhaust emissions are reduced by up to 50%."

 

[huskihl]

These two links are from Stihl UK
( same EU Emissions Directive Stage II with rest of EU ) .

https://m.stihl.co.uk/STIHL-Product...-work/287735-130/MS-500i-Petrol-Chainsaw.aspx
https://m.stihl.co.uk/STIHL-Product...ork/22284-130/MS-661-C-M-Petrol-Chainsaw.aspx
Check out the "features" tab ,on
both .

"1-in-4 channel technology. The economical STIHL 2-MIX engine with 1-in-4channel technology features a high torque over a wide speed range. The chainsaw provides fuel savings of up to 20% compared to STIHL two-stroke engines in the same performance class without 2-MIX technology. Exhaust emissions are reduced by up to 50%."

I see it. But it isn’t correct.

 

[KostasVolos]

I see it. But it isn’t correct.

In what way ?
( I trust your opinion ,
but just being curious )

 

[huskihl]

500i intake




661 intake




And here’s a 400cm, which is a strato “2 mix” motor. They have a narrow intake because of the cutout in the piston. And you can see the strato ports directly under the transfer ports

 

[huskihl]

661 intake…1 hole straight through to intake port



500i uses a bolt on boot, but still 1 hole straight through




And the strato ms400cm. The lower hole is the intake. Upper hole branches left and right to the strato ports I posted above

 

[bwalker]

@huskihl doesn't the 500I, 661 and 461 use what's called delayed scavenging where by exhaust is backed up into the transfer ports? I've never looked at any of the above or checked out their port timings, but I seem to remember reading this.
The other thing is 2mix and 4mix are just marketing BS for Stihls 2 stroke and *******ized 4 stroke lines.

 

[Franny K]

This is from the 500i manual on the Stihlusa site today. There are registered trademarks and common law trademarks and 2-mix is missing at this time. There probably is some way to get a definition.

 

[cscltd]

2-mix wording may have been used before in various product and companies that patent could not be applied for

 

[huskihl]

@huskihl doesn't the 500I, 661 and 461 use what's called delayed scavenging where by exhaust is backed up into the transfer ports? I've never looked at any of the above or checked out their port timings, but I seem to remember reading this.
The other thing is 2mix and 4mix are just marketing BS for Stihls 2 stroke and *******ized 4 stroke lines.

They claim that, but there is just as much black inside used-cylinder transfer ports in any saw with a restricted muffler. It’s not hard to tell when back-stuffing is going on