40:1 mix ration on m-tronic saw

[livemusic]

I never thought about it but I run 40:1 ratio on all saws and just bought a Stihl ms400cm, which is an m-tronic saw. Is 40:1 not good for the ms400? It runs great, just need to know. I assume that it adjusts for whatever fuel mix is used but you know what assuming does.

EDIT: Disregard this post, I found this thread from 2019. Consensus seems to be that 40:1 is ok...
LINK: older thread on this subject

 

[U&A]

Honestly it depends on the oil. Yup i said it.

Some m-tronic/auto tune saws will run great on 40:1 on one oil and not on another.

Just my experience with a 562.
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Sent while firmly grasping my Redline lubed Ram [emoji231]

 

[Tomos770]

Honestly it depends on the oil. Yup i said it.

Some m-tronic/auto tune saws will run great on 40:1 on one oil and not on another.

Just my experience with a 562.
[emoji1303]


Sent while firmly grasping my Redline lubed Ram [emoji231]

Could it be because modern Di-Tech scooters also have the same problem....

....some 2stroke oils trap moisture from the air.....some have "demulsifier" properties...

Dont know how autotune or M-tronic is working.....but most probably its the same thing as "Di-Tech" technology....where moisture from the air form emulsion when mixed with 2stroke oil inside the carburetor or injector....will try to find a proper link for that!

 

[Tomos770]

Ekola....

https://www.af1racing.com/OEM-Aprilia-Emulsion-Bleed-Valve-Kit-8276090
I know that my friend had that problem with water in injection system.... And it faded away with Motul 710 2t (ester oil)

 

[Tomos770]

Problem explained...
https://www.apriliaforum.com/forums...ly-figured-out!!!-You-ll-want-to-read-this!!!

 

[U&A]

Ekola....

https://www.af1racing.com/OEM-Aprilia-Emulsion-Bleed-Valve-Kit-8276090
I know that my friend had that problem with water in injection system.... And it faded away with Motul 710 2t (ester oil)

Now....

Please for all our sakes post a pic of your friends Aprilia!!

[emoji16]


Sent while firmly grasping my Redline lubed Ram [emoji231]

 

[link]

I blend my own gasoline and uses synthetic 2-stroke oil, I use 2,5% - that sould be about 40:1.
I have two tanks on my new MS241 now and I have not noticed any problems, quite on the contrary.

Engines with fuel injectors are usually sensitive to water in the gas, that would be like the 500i.

 

[Backstage]

I can say that the autotune huskies are also sensitive to water. Not sure about mtronic or injected.

40:1 has the tendency to run hotter from what I’ve read on the infallible interwebs. These saws are already pushed to that limit. Worth considering.

 

[link]

That sounds very strange, that better lubrication heats up the engine.

 

[Backstage]

Possibly better lubrication, yes, but the oil burns as well as the gas, and burns hotter.

Would be interesting to get a temperature reading on the same saw ran similarly on both fuels.

 

[link]

Ah, I see. I better go back to 2% or 50:1 after the first few tanks then. I'm not too worried though, when I'm running in the saw I dont run it "hard and long".

 

[StihlPotlicker]

I run 32:1 on my ported saws with Shaeffers 9000 syn. with 91 e free gas. even ran it on a non ported 661C first gen. then used that 661C for my logosol F2 + chain saw mill no issues. i have been running a G660 at 32:1 cm for the last 1yr without any issues.

 

[JRM]

I can say that the autotune huskies are also sensitive to water. Not sure about mtronic or injected.

40:1 has the tendency to run hotter from what I’ve read on the infallible interwebs. These saws are already pushed to that limit. Worth considering.

It sure does, to an extent. The richer mixtures seal the rings better than lean mixtures, create more power, and to an extent, create more heat (work)

One of a few reasons I personally would never run 100:1 mixtures without some real tuning.

 

[CaseyForrest]

I run 40:1, and have forever, in all my saws. From 241 up to 661, M Tronic and FI. Either Klotz R50 or Stihl HP. Been using the HP lately because I have a crap ton of it to burn through. Will likely switch back to Klotz once its all gone.

 

[StihlPotlicker]

I run 40:1, and have forever, in all my saws. From 241 up to 661, M Tronic and FI. Either Klotz R50 or Stihl HP. Been using the HP lately because I have a crap ton of it to burn through. Will likely switch back to Klotz once its all gone.

i use my HP for when i need to burn junk wood, after i had "tar" issues using it at 40:1

 

[ihookem]

You know, it would be interesting to have real testing being done on saws that run 100/1 , 50/1 and 40/1 to really see a difference if it is possible. Like how much compression is there when running 100/1 compared to 40/1? I still just run Amsoil Sabre with 2oz. per gal. and that is 64/1. I used to run 1oz per gal. for 128/1. I dont know why , but I did it for a long time. I also ran a Merc 25 horse with 100/1 cause the manual said it was ok if used several times per week in the summer months.

 

[Andyshine77]

You get more compression with more oil, do to better ring sealing. More oil does not cause more heat, the stuff you see on the internet/Youtube do not even have the basic scientific controls, such as tuning for each oil, obviously a non issue with TA and Mtronic models.

The auto adjusting models prefer the thinner oils over the real viscous oils like model 800, Klotz R50 and so on. In stock saws 40:1 is great in stock saws, and in ported saws 40:1 or 32:1 is fine.

The oils I prefer in no particular order.

Maxima K2 or SuperM.

Motul 710, ported standard carb models 800 is great as well.

Amsoil Saber or Dominator.

Honda HP2.

Echo RedArmor.

 

[Colonel428]

Good stuff Andy.

 

[bwalker]

Now....

Please for all our sakes post a pic of your friends Aprilia!!

[emoji16]


Sent while firmly grasping my Redline lubed Ram [emoji231]

Di tech and Myronic are not similar at all. Not even close.

 

[bwalker]

I run 32:1 in my 400C. It runs perfect.