Stihl not 2T?

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May 1, 2012
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Indiana
So I just bought a new trimmer. Stihl FS111MD

I just used it. I was shocked. This isn't a 2T!!!

They made a 4-stroke that burns mixed gas?? Am I that far behind on these things?
 
So I just bought a new trimmer. Stihl FS111MD

I just used it. I was shocked. This isn't a 2T!!!

They made a 4-stroke that burns mixed gas?? Am I that far behind on these things?
About 20 years behind.
Screenshot_20220823-194341_Brave.jpg
 
By the way, while those 4mix engines are not really "ultra high performance" they are an interesting concept and can run exceptionally well.

Interestingly, this kind of design can supercharge itself as the crankcase can be used to draw in air/fuel, every time the piston moves up, just like a two stroke. But the intake valve opens in conventional 4 stroke manner. Meaning it can have two volumes of air pulled in for each intake valve opening. The result is 7 psi of boost at full power.
 
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Nope not for me that's alot of moving parts power to Weight ratio blows FS 240 go big and true 2stroke absolutely best trimmer I've ever had will do absolutely anything. Dealer talk me out of a 4mix and glad he did.
 
Congrats on your purchase. I have an FS111 with the bike handlebar since I use it for heavy brush clearing. You can also feather the throttle easily for trimming bit I don't have much of that. I use either a blade or 095 line like this one:
You could pay more for the 131 or go with a two stroke if that's your game but nothing wrong with the FS111. Get choppin!
 
By the way, while those 4mix engines are not really "ultra high performance" they are an interesting concept and can run exceptionally well.

Interestingly, this kind of design can supercharge itself as the crankcase can be used to draw in air/fuel, every time the piston moves up, just like a two stroke. But the intake valve opens in conventional 4 stroke manner. Meaning it can have two volumes of air pulled in for each intake valve opening. The result is 7 psi of boost at full power.
I’ve had the “forced induction” thought on these before but was afraid to say it lest I sound like an idiot!

I guess the effect is there in a 2 stroke also(it’s kind of how the whole thing can work in the first place) but it’s kind lost also since it’s happening with the exhaust port also uncovered. With these engines, you get the benefit of the crank case pressure for(more or less) a full intake stroke.
 
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