O2 Sensors, oh my...

[Ozhoo]

It was only a matter of time and it seems like a logical step for intelligent fuel control.

Husqvarna was just granted a patent for "Adjusting Of Air-Fuel Ratio of a Two-Stroke Internal Combustion Engine" via a closed loop. Muffler mounted O2 sensor provides the A/F feedback.

Patent attached

 

[lone wolf]

It was only a matter of time and it seems like a logical step for intelligent fuel control.

Husqvarna was just granted a patent for "Adjusting Of Air-Fuel Ratio of a Two-Stroke Internal Combustion Engine" via a closed loop. Muffler mounted O2 sensor provides the A/F feedback.

Patent attached

View attachment 606047

View attachment 606048

Gonna cause a lot of problems troubleshooting anything wrong!

 

[Thommo]

It will be interesting to see how long the oxygen sensor lasts with a coating of two stroke oil

 

[Chris-PA]

The idea is to use a muffler with baffles to fully mix the exhaust and scavenged air so that a conventional O2 sensor can be used. This would be used on a strato engine, presumably so that there is not such an excessive amount of scavenge lost fuel too. By mixing the scavenged air and the exhaust, and controlling to a Lamba of 1, the actual mixture will be a bit richer than 1, which is what they want.

The intent is to follow up the with a 3-way catalyst after the O2 sensor to more completely clean the exhaust.

This would replace the "lean-out test" of the present feedback systems, which at the moment is the only practical way of sensing fuel/air mixture.

 

[ironman_gq]

You could probably do something similar with a pyrometer and modify the lean back programming to hit a targeted EGT. Pyrometers are much more robust than an O2 sensor and quite a bit cheaper.

 

[anlrolfe]

So much for muffler mods...

 

[1Alpha1]

Won't be too long before you have to take a laptop computer with you when you go cut wood.

You know......to make sure your chainsaw is performing correctly.

 

[Ozhoo]

Won't be too long before you have to take a laptop computer with you when you go cut wood.

You know......to make sure your chainsaw is performing correctly.

Stihl is working on adding a solar panel The idea is to power on the electronics before the flywheel starts turning

 

[pro94lt]

Closed loop is great!

 

[earlthegoat2]

I hope someone is quick to develop flash tuners for them.

 

[jltrent]

These chainsaws are destroying all our air, want be long before they are outlawed.

 

[Bobby Kirbos]

I have a sneaking suspicion that this came about due to the predatory EPA that we had under the previous president. If they could bring it to the market, they would be the favored child and get all of the .gov contracts. I wonder, given the EPA under President Trump, if they will simply sit on the patent.

If they put it in ALL of their saws (and the other brands that are under the same roof), they're going to take a hit in the consumer sector. What do you mean $500?!?!?!? Last year's model of this same saw only cost $200.

For the guys who make a living with these things - you're going to absorb the lion's share of the price increase. They can't hit the consumer with the full price increase, so they'll raise the price on the consumer grade stuff by a small amount and the price increase on the pro-grade stuff will cover the difference.

PLUS, if you've ever had an O2 sensor fail on your car and it goes into retard "get me home" mode - that's not something you want to deal with when you absolutely need your saw to run right the fk now - thinking fire fighters, etc.

If they do implement this across their entire product line, I see a lot of new saws with after-market conventional carbs (if brand loyalty outweighs price), or a lot of new saws that are NOT Husqvarna.

 

[1Alpha1]

I'm still waiting for a diesel powered chainsaw.

I wonder if it will have a DEF tank?

 

[Bobby Kirbos]

I'm still waiting for a diesel powered chainsaw.

I wonder if it will have a DEF tank?

Nah, propane, those 1# green bottles that you use for camping.