How does Auto tune work?

[Daniël Bos]

Someone in America has fitted a normal carb

 

Not all Americans are clever it seems...?

 

Seems silly, like buying a Tesla S and swapping the electrics for a small block V8?

[wyk]

Not all Americans are clever it seems...?

 

Seems silly, like buying a Tesla S and swapping the electrics for a small block V8?

 

I would hardly call the current generation of MTronic and Autotune comparable to a Tesla S...

[peatff]

Not heard that Eddy, i know somebody has taken the unit apart and fitted a screw so to adjust the fuel flow, as i understand it you cannot change just the carb to a standard one as auto tune is controlling the ignition, not too sure why anyone would want to?

 

Does it definitely control the advance at different points in the rev range ? If you had a saw and the auto packed up and you could salvage it with a £20 ebay Zama or buy a £200 dealer only part to replace it which would you do ? Lots of people spend money hacking the software on their cars, are they all stupid ?

[adw]

It does control the ignition timing, i think the 560 already kicks out enough power for most people, so as i said why do you want to tamper with the software, what are you saying costs £200?

[wyk]

Does it definitely control the advance at different points in the rev range ? If you had a saw and the auto packed up and you could salvage it with a £20 ebay Zama or buy a £200 dealer only part to replace it which would you do ? Lots of people spend money hacking the software on their cars, are they all stupid ?

 

I was quoted 100 quid for a 241C MT carb today.

[peatff]

It does control the ignition timing, i think the 560 already kicks out enough power for most people, so as i said why do you want to tamper with the software, what are you saying costs £200?

 

Just guessing at what a dealer would want for the carb with electronics on it as I can't find a price for them anywhere. Do you have a list ?

[bunnybasher100]

I know the 540xp is under £70 but as in 2 parts one of which won't go wrong.

 

 

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[Eddy_t]

It does control the ignition timing, i think the 560 already kicks out enough power for most people, so as i said why do you want to tamper with the software, what are you saying costs £200?

 

 

That's one part of the whole system I can't understand, how does it control the timing, the timing is fixed point (ie, the magnets). This produces a pulse, unlike the old points ignition, which charged a capacitor and created a short circuit as its timing. After all, why bother with a key on the flywheel?

Next question is why the Americans advance the flywheel and gain power if the autotune alters the timing?

How does it know the optimal time? Does it know? Can it think? What does it think of the flakey silver paint?

No, it's a chainsaw! It creates a spark by induced current and multiple coils around a lump of iron that operate at peak speeds. Impulses cannot be stored, advanced or retarded, especially by a microchip and some magnetic valves. Altering the timing is the same regardless of model, era or any fancy gadgets.

[wyk]

Yeah, Bitch! MAGNETS!

 

As the RPM's climb, the amplitude of the wave that triggers the system to fire increases, thus advancing it. It is built in to the ignition system design(whether saw or bike, etc). Thus, the saw is easier to start at lower RPM, and has the advance it needs at higher RPM. I know Husky have been more aggressive with their ignition advance lately, and I find little benefit adding ignition timing to most newer Huskies with limited coils. I have assumed Stihl were pursuing something similar, as I have been told advancing the ignition on MT saws is of little benefit.

 

And, to be frank, I feel ignition advance is really only needed if you have a GTG saw, or are competing. In the field, I prefer no modified advance.

 

[ame]

[/ame]

[forest tink]

what is the price for a 576xp autotune carb just out of interest ?