Future plans for making auto tune 3120xp?

[Adirondack]

I really like the auto tune feature of my 550 XP. If Husqvarna is planning on coming out with the auto turn version of the 3120xp I want to wait and purchase one. Does anyone know?

 

[Big_Wood]

there may very well at some point be an auto tune 120cc but it's a long long ways away. everything else will be AT before that. i would guess stihl would put it on a 120cc first as they rushed out all their other models with it.

 

[Adirondack]

Thanks. What about the 395xp in auto tune?

 

[Conquistador3]

I think that, at least for their top products, most major manufacturers are carefully weighing to skip Autotune/M-Tronic altogether and jump to fuel injection.
Autotune is great and works well, but it's really nothing more than a stop-gap measure.
I suspect that famous Honda two stroke patent floating around is not really aimed at manufacturing a Honda-branded engine, but at selling two stroke DFI patents and/or Keihin fuel system components to other manufacturers. If someone has the resources to make it work, and work well, that's Honda.

 

[RIDE-RED 350r]

I think that, at least for their top products, most major manufacturers are carefully weighing to skip Autotune/M-Tronic altogether and jump to fuel injection.
Autotune is great and works well, but it's really nothing more than a stop-gap measure.
I suspect that famous Honda two stroke patent floating around is not really aimed at manufacturing a Honda-branded engine, but at selling two stroke DFI patents and/or Keihin fuel system components to other manufacturers. If someone has the resources to make it work, and work well, that's Honda.

And Rotax.... Their E-TEC system they have been using on their 2-stroke snowmobiles since 2009 is quite amazing.

Only thing about these modern hi-tech EFI systems for 2-stroke engines is the electrical needed to run them. The Rotax E-TEC system uses electromagnetically actuated fuel injectors. Plus there are other engine monitoring systems in play that are needed to make the whole system work properly. My layman's guess is that the size and output requirements to operate such systems may still be impractical for implementation on a power saw.

But technology advances further every day with components getting smaller and smaller and more capable of doing the jobs needed to do.

I am sure it's coming at some point.

 

[Conquistador3]

And Rotax.... Their E-TEC system they have been using on their 2-stroke snowmobiles since 2009 is quite amazing.

Only thing about these modern hi-tech EFI systems for 2-stroke engines is the electrical needed to run them. The Rotax E-TEC system uses electromagnetically actuated fuel injectors. Plus there are other engine monitoring systems in play that are needed to make the whole system work properly. My layman's guess is that the size and output requirements to operate such systems may still be impractical for implementation on a power saw.

But technology advances further every day with components getting smaller and smaller and more capable of doing the jobs needed to do.

I am sure it's coming at some point.

And Stihl already has a batteryless cut-off saw out while battery-less fuel-injected (four stroke and two-stroke) dirt bikes have been around for years. Honda was the first to introduce it on their Montesa trials bikes in 2005. Hell, Honda had a DFI two stroke bike back in 1994 which worked, and worked well.

If saws are the same as dirt bikes, the only restraining factor is money. A DFI two stroke would cost more than a FI four stroke and far more than a carb two stroke. Sure, plenty of advantages but price trumps everything these days. No more Echo twin cylinder saws or Wankel-powered Dolmar's...

 

[RIDE-RED 350r]

EPA mandates do drive these types of advances forward though, for better or for worse.

I am not as familiar with Honda's DFI 2-stroke tech (I'm stuck in the old school ) as I am with Rotax's as I was heavily into snowmobiling up till a few years ago... I doubt you will ever see a Honda DFI 2-stroke mass produced as they are fully invested in 4-stroke in the world of ATV and Bike Moto-X. I have seen a patent complete with blueprints as recent as the mid 2000's online for a new DFI Honda 250, but nothing ever came of it......

But I can tell you that when the EPA stiffened the standards applied to the snowmobiles, all the major manufacturers except Ski-Doo started putting most of their eggs in the 4-stroke basket. Yamaha being the one company to go all-in for 4-stroke, Cat has a mix that as far as I know is still about evenly split between 2 and 4-stroke models, Polaris leans more 2-stroke and Ski-Doo remaining mostly 2-stroke with 2 or 3 different 4-stroke mills so far. I would say though that Polaris has approached things very similarly to Ski-Doo. But Rotax was the first in snowmobiling to put out a real DFI system. This system came to Rotax when they bought Johnson/Evinrude marine, who had these systems employed on 2-stroke outboard motors since the mid 1990's. The basics were there, and some tweeking was necessary to employ them on sled engines. The timing was about perfect and so far those E-TECs have defied the conventional wisdom that 2-strokes are soon to be a thing of the past.

None of this would have happened were it not for EPA clamping down on this industry. Myself, I'm not a fan of the power they wield, but that's another conversation for another thread.

I think what we are seeing in chainsaw world is the beginnings of the same sequence of events... just 10-15 years behind.

 

[Chris-PA]

If saws are the same as dirt bikes, the only restraining factor is money.

But they're not. Size and weight are big issues, and if it's not direct injection it has no advantages at all over a feedback carb on a single cylinder 2-stroke. Regardless of if you use an injector or a venturi/jet to deliver the fuel, you still need basically the same scheme to measure and control the mixture in closed loop.

However you must have a system that is mostly correct even without feedback. A carb is a simple passive device that will still work reasonably well open loop. A fuel injection system is an active device that does nothing without active control systems even when it is open loop.

 

[Conquistador3]

But they're not. Size and weight are big issues, and if it's not direct injection it has no advantages at all over a feedback carb on a single cylinder 2-stroke. Regardless of if you use an injector or a venturi/jet to deliver the fuel, you still need basically the same scheme to measure and control the mixture in closed loop.

However you must have a system that is mostly correct even without feedback. A carb is a simple passive device that will still work reasonably well open loop. A fuel injection system is an active device that does nothing without active control systems even when it is open loop.

Those were exactly the same doubts we had back in the days for trials bike, were size and, even more critically, weight are paramount concerns. When Honda announced a liquid cooled, fuel injected four stroke commercial trials bike, we all thought it would be a lumbering behemoth. It wasn't.
The doubts you express are well grounded in reality, but those problems are not impossible to solve, especially given the solutions already exist and it's all a matter of miniaturization.
I think the main driver here will be emissions: as power equipment goes, legislation has not proceeded according to a schedule but by fits. If legislation stays as it is, you are most likely right and there will be no need for fuel injection. If not, fuel injection will surely become much more appealing.

 

[zogger]

3120 is a big saw. Anyone take any measurements to see if perhaps some already existing tech with FI or an active style computer carb rig, etc., might be made to fit?

 

[Chris-PA]

Those were exactly the same doubts we had back in the days for trials bike, were size and, even more critically, weight are paramount concerns. When Honda announced a liquid cooled, fuel injected four stroke commercial trials bike, we all thought it would be a lumbering behemoth. It wasn't.
The doubts you express are well grounded in reality, but those problems are not impossible to solve, especially given the solutions already exist and it's all a matter of miniaturization.
I think the main driver here will be emissions: as power equipment goes, legislation has not proceeded according to a schedule but by fits. If legislation stays as it is, you are most likely right and there will be no need for fuel injection. If not, fuel injection will surely become much more appealing.

I disagree on several points. A bike is an order of magnitude larger than a saw, so the solutions developed there don't apply directly, and direct injection systems have not been developed for OPE like chainsaws.

If it's not direct injection then future tighter emissions limits will not drive indirect injection since it offers no advantages over feedback carbs, and requires all the same feedback control system plus all the parts needed just to make it work.

It's not useful just to extrapolate past trends or what was done with other equipment - the problem being solved is different, as are the requirements. I think people miss just how big an improvement feedback carbs are (in terms of emissions and wasted fuel), as they underestimate just how bad traditional carbs are. They are so small and mounted on such small engines, how could they be so bad? Yet they are, due to a fundamental design characteristic that other carbs don't have.

So the improvement from traditional carbs to feedback carbs is very large, especially when combined with strato to reduce scavenging losses (which probably would not work as well on a bike engine). All of that was achieved with a minor mod to a traditional carb, plus some extra electronics in existing ignition module - very little additional space, weight or cost. To go further will be diminishing returns for much greater tradeoffs. My bet is that 4-stroke would be easier than direct injection.

 

[Big_Wood]

AT and Mtronic ain't going anywhere anytime soon fella's. manufacturuers will bleed all profits they can out of the idea before they come out with a new one. i like needles and screwdrivers myself.