ESE's works engine tuner

[flyonly]

This is automatically tuning system FAI EFI for 4-stroke. Just start and play bt throttle few minutes to calibration.
https://www.ebay.com/itm/FAI-motorcy...-/273178456487
Seems should be simple and elegant way use it on 2-strokes?

Where would you put the O2 sensor on a 2 stroke? Middle or stinger cone?


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[TZ350]

my guess is it generic pics or its tucked in behind ,its listed in the blurb..........
009 oxygen sensor fault. https://www.ebay.com/itm/FAI-motorcy...-/273178456487

its also in a photo

Good spotting, I didn't see that. Wide or narrow band O2 sensor and what air/fuel ratio or lambda would the CPU be automatically tuned to?

[husaberg]

Good spotting, I didn't see that. Wide or narrow band O2 sensor and what air/fuel ratio or lambda would the CPU be automatically tuned to?

No idea but as its for a foul stroke so i guess stoich.
pretty sure one of those you used had a autotune function?

[TZ350]

Where would you put the O2 sensor on a 2 stroke? Middle or stinger cone?

I put mine in the rear cone near the stinger.

[TZ350]

pretty sure one of those you used had a autotune function?

Problem with any auto tune for a two stroke is accounting for the oxygen in the short circuiting air.




The cylinder can have a perfect air/fuel mixture trapped inside when the exhaust port closes but the O2 sensor still thinks it sees a lean condition. The effect varies depending on TPS and RPM and whether its on the pipe or not. The best result is at WOT and peak torque where there is maximum trapping efficiency and the least short circuiting. Every where else is worse.

You can have a target air/fuel map for the ECU to aim at. But for every RPM vis TPS position on the map the air/fuel ratio to look for is still pretty much a guess. In my experience the motor can be running perfectly but the indicated air/fuel ratio can be anything from 18:1 to 10:1 and changes continuously as the load and rpm changes.

[husaberg]

Problem with any auto tune for a two stroke is accounting for the short circuiting air.




The cylinder can have a perfect air/fuel mixture trapped inside when the exhaust port closes but the O2 sensor still thinks it sees a lean condition. The effect varies depending on TPS and RPM and whether its on the pipe or not. The best result is at WOT and peak torque where there is maximum trapping efficiency and the least short circuiting. Every where else is worse.

You can have a target air/fuel map for the ECU to aim at. But for every RPM vis TPS position on the map the air/fuel ratio to look for is still pretty much a guess. In my experience the motor can be running perfectly but the indicated air/fuel ratio can be anything from 18:1 to 10:1 and changes continuously as the load and rpm changes.

Frits sumed it up
insert quote here.

So you are aware that a Lambda sensor cannot tell you at all if a mixture is rich or lean. It can only tell you whether there is oxygen present in the exhaust gases.
Scavenging losses at low revs as a result of washed-through mixture will make sure of this oxygen presence. And misfiring because of an overly-rich mixture can enhance this presence even more, so enrichening the mixture at low revs may well worsen the 'lean' situation.
There are three things you can do about it. The first is copying Flettners cylinder with variable transfer timing. The second, somewhat simpler option, is to shift down when the engine threatens to drop out of its power band. The third option is to get an engine without a power band (and without two-stroke power),
a so-called foulstroke or Falschtakter .

.

And how is this system going to detect a lean condition? An O2-sensor cannot do that; it can only detect the presence of unused oxygen in the exhaust gases.
If the mixture is so rich that the engine misfires, that O2-sensor will detect O2 and then this wonderful system will enrichen the mixture even more. Been there....
...

[TZ350]

.
Yes, auto tune is not so straight forward with a two stroke.

[jbiplane]

.
Yes, auto tune is not so straight forward with a two stroke.

I saw at least perfectly working autotune systems
2-stroke 3w model engines
2-stroke Stihl 500 chainsaws and cutters
Mixture lean on medium rpm and rich on high revs

Zhejiang Fai Electronics Co. have 2-stroke solutions as well
http://www.freepatentsonline.com/6964263.pdf

Some additional info
http://fuyangdali.com/en/product/33.html
http://3moon-house.com/upload/201607...1739542500.pdf

[Pursang]

I put mine in the rear cone near the stinger.

What about using a Hydrocarbon or CO or CO2 sensor here instead of looking for O2?
Any of these would be a better indicator of fuel mixture/combustion efficiency.

For a race engine a base level of hydrocarbon would indicate that you have sufficient fuel to consume all the O2 available.
For road use aiming for max CO2 would ensure complete combustion. (and the possible wrath of concerned citizens).

Cheers, Daryl

[SwePatrick]

Lubrication and cooling bigend connectionrod.

As my bigend seized i´m about to rebuild it with a fresh rod, but i´m thinking maybe leave the axial plates/discs on the bigend and guide the rod in the piston instead.
I figure i might loose some friction also, and by this not build as much heat in the bigend.
And when having no axial plates/discs there are more space to cool it and lubricate it.

Is it a good idea?

[TZ350]

What about using a Hydrocarbon or CO or CO2 sensor here instead of looking for O2?

Hi Daryl. I had not thought of that. I wounder if its a practical possibility .... interesting....

[diesel62]

What about using a Hydrocarbon or CO or CO2 sensor here instead of looking for O2?
Any of these would be a better indicator of fuel mixture/combustion efficiency.

For a race engine a base level of hydrocarbon would indicate that you have sufficient fuel to consume all the O2 available.
For road use aiming for max CO2 would ensure complete combustion. (and the possible wrath of concerned citizens).

Cheers, Daryl

I found putting the sensor there gives bad readings. I think the gas is too turbulent. Works better at the end of the stinger as there is no reversion

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[TZ350]

i´m thinking maybe leave the axial plates/discs on the bigend and guide the rod in the piston instead. Is it a good idea?

The Suzuki RGV250 did this and I used one of their Rod kits in my single cylinder 125 for years, it worked well.



The smaller washers next to the rod are used to centralize the bigend bearing. The rod centralizing washers can be seen on the little end pin.

[TZ350]

I found putting the sensor there gives bad readings. I think the gas is too turbulent. Works better at the end of the stinger as there is no reversion .

Muffler end or the cone end of the stinger? I think Wobbly has talked about doing it that way too.

[diesel62]

Muffler end or the cone end of the stinger? I think Wobbly has talked about doing it that way too.

Outlet of muffler. I made an adapter so it didn't impead the gas flow. Just make sure you don't have any air leaks between muffler and expansion or stinger

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