Stihl MS881! The rumors begin

[huskyboy]

I thought strato saws have a separate butterfly above or below the carb for the fresh air charge. 881 doesn't have that. It does have a plastic divider in the manifold.

Maybe I dont know what strato is.

Watched a video from stihl on 2mix engine. https://www.stihl.com/2-mix-technology-economical-and-with-good-lugging-power.aspx
Not sure how that works with no air valve.

Strato don’t have to have separate butterflies. They can have a single butterfly and divided carb. Some examples are the 372xtorq and 462c.

 

[jmester]

So port layout is the deciding factor not the carb or divider in intake manifold. The strato ports are above and beside the intake port?
@huskyboy

 

[Sagebrush33]

So port layout is the deciding factor not the carb or divider in intake manifold. The strato ports are above and beside the intake port?
@huskyboy

Yes... I'm used to 4-stroke but all engines are basically air pumps. They draw air and fuel in and pump it out as exhaust. The tricks start with increasing flow in the engine before adding fuel. 2 or 4-stroke. This is how I understand it anyways...

 

[deye223]

Strato a don’t have to have separate butterflies. They can have a single butterfly and divided carb. Some examples are the 372xtorq and 462c.

Yep and on the pro saws I think the 1st was the 261

 

[Stihl Potlicker]

 

[Stihl Potlicker]

the twins like it lol. hopefully i will be able to run it this wkend. last 2 were a wash out.

 

[Sagebrush33]

To the twins that is like the sword of Excalibur.

Nice saw man.

 

[Stihl Potlicker]

To the twins that is like the sword of Excalibur.

Nice saw man.

right. they have been lol. they don't play with their toy saws any more LOL. their wives can thank me later for the addiction LOL

 

[Brewz]

I picked up my new 881 yesterday.
Today it fell apart on my workbench..... Ooops.



First thing I checked was the coil. Its no longer the same footprint as the 880 and 361 coil. It is however the same footprint as a 661 Mtronic coil..... I dare say for the future.
I have ordered one of the unlimited aftermarket 880 coils to try and also have an OEM 362 coil here to try but will need to make a bracket to retro fit them.

As stated above, the intake has a small square case feed intake with strato feed ports feeding the sides of the piston. No fresh air feed, both case and strato's are fed wet mix.
Transfer feed is same style as 461/661, bottom front fed from case.

So far I have cut squish and base 30 thou, marked out the cylinder for porting tomorrow and removed the limiters from the carb.
It wont need much porting, ports are really good and so is timing, just needs adjusting from the base cut.
Will open up the muffler, mod the carby a bit and run it up on the stock coil to check timing and advance curve if any with a timing light.
That will give me a good baseline to aim for with an unlimited coil.

The saw itself feels quite like an 084. Not as heavy or bulky as an 880.... I really like it.

 

[deye223]

I picked up my new 881 yesterday.
Today it fell apart on my workbench..... Ooops.

View attachment 297793

First thing I checked was the coil. Its no longer the same footprint as the 880 and 361 coil. It is however the same footprint as a 661 Mtronic coil..... I dare say for the future.
I have ordered one of the unlimited aftermarket 880 coils to try and also have an OEM 362 coil here to try but will need to make a bracket to retro fit them.

As stated above, the intake has a small square case feed intake with strato feed ports feeding the sides of the piston. No fresh air feed, both case and strato's are fed wet mix.
Transfer feed is same style as 461/661, bottom front fed from case.

So far I have cut squish and base 30 thou, marked out the cylinder for porting tomorrow and removed the limiters from the carb.
It wont need much porting, ports are really good and so is timing, just needs adjusting from the base cut.
Will open up the muffler, mod the carby a bit and run it up on the stock coil to check timing and advance curve if any with a timing light.
That will give me a good baseline to aim for with an unlimited coil.

The saw itself feels quite like an 084. Not as heavy or bulky as an 880.... I really like it.

Being the same as a 461 and selling the design I'm hoping the 881 is a real torque monster .

 

[Nutball]

Not even a fresh air divider inside the carb?

 

[Brewz]

Not even a fresh air divider inside the carb?

Nope.
Fuel is fed in from the bottom of the carb so will probably preferentially feed the lower intake before the upper strato’s but no dedicated divider.

 

[Nutball]

But the boot is divided right? That's like the 201t, and I'm sure many others that I haven't looked in.

 

[Brewz]

Yes it is.
Like I said, fuel will mostly go to the case but the upper strato ports are not pure fresh air feed.

I’m quite happy with that to be honest

 

[Brewz]

 

[ferris]

@Brewz
What did u change to fit the 362 coil?

 

[Brewz]

Nothing.... just gotta make it fit

 

[deye223]

Hmmmm hey brewz just wondering how the 881 is going .

 

[Stihl Potlicker]

 

[Stihl Potlicker]