ESE's works engine tuner

[Flettner]

Alcohol fuel, time for injection.

[peewee]

naw mate im not putting no more money or time into it . floatbowl is off and ill fix the leak tomorrow. as for why it wouldn't start, im not sure. has always started easily in the past few months but it did give me trouble 2weeks ago also. since its getting colder maybe that has something to do with it. ive heard people have to warm the engine block or fuel sometimes on methanol engines. fuel temp was 50F today when I checked it. ill get it sorted sooner or later. maybe give the intake a squirt of starting fluid next time

[Flettner]

That's why they make E85, not E100, a little petrol will assist start and speed the burn up. Even with E85 I still have trouble firing up my 350 sometimes. A little petrol prime is in order when this happens.
https://youtu.be/CnIemdISKrM

[teriks]

naw mate im not putting no more money or time into it . floatbowl is off and ill fix the leak tomorrow. as for why it wouldn't start, im not sure. has always started easily in the past few months but it did give me trouble 2weeks ago also. since its getting colder maybe that has something to do with it. ive heard people have to warm the engine block or fuel sometimes on methanol engines. fuel temp was 50F today when I checked it. ill get it sorted sooner or later. maybe give the intake a squirt of starting fluid next time

Starting methanol engines in the cold can for sure be a pain in the...
Get some heat into the engine and try again.
A primer as Flettner suggests is probably the easiest way.

[SwePatrick]

naw mate im not putting no more money or time into it . floatbowl is off and ill fix the leak tomorrow. as for why it wouldn't start, im not sure. has always started easily in the past few months but it did give me trouble 2weeks ago also. since its getting colder maybe that has something to do with it. ive heard people have to warm the engine block or fuel sometimes on methanol engines. fuel temp was 50F today when I checked it. ill get it sorted sooner or later. maybe give the intake a squirt of starting fluid next time

Just squirt some petrol into carb before trying to start.
I´m using a 'squirt bottle' as the big guys in dragracing, supersimple!

Always starting on 1st or 2nd kick when cold with that. =)
I have started it down to about 15f with no hassle.

Get a richer needle!
If just adding more and more powerjets i figure the lowspeed system still is very lean?
My jetting on 211cc and ~75.5hp at the crank is in Keihin sizes: 110 pilot, 265 main, homemade powerjet opened about 1/4-1/3 turn.
Starting with 1/4, and when engine is hot i turn it more open to about 1/3.(i figure it starts to free up the containing oxygen, like 'nitro light' effect)
Still when engine is really really hot after a hard dynosession with about 10 pulls in a row it tends to runaway on idle, i might need 120-125 in pilot when hot.
But it is so much harder to get it to warm up properly with bigger than 110.

This with only methanol fuel.
If i were about to run say 20% nitro i would increase pilot a lot, just to make sure engine won´t runaway.

Rgds.

[TZ350]

I'd like to see injector pulsewidth in that graph as well

Pink line is injector pulse width. Blue RPM and Brown is wide band O2 sensor.

WOT, same RPM, same injector pulse width, different Lambda.

I think Nath88 is onto it.

Same rpm, same throttle position, different airflow.

Attachment 332725

[TZ350]

My first efforts at trying Nath88'ts idea of using the strength of the returning pressure pulse at the exhaust port window to determine if the motor is firing or not did not go so well.

The small bouncing ball one way valve I tried to use stuck open and all I got was the average of pressure and suction pulse. It was not very useful.



Tonight I tried a different style of one way valve. A duck bill, it acts like a reed valve, easy to open and naturally shuts again and does not hang up with gummy oil like the ball valve did.



The pressure bleed was taken from the header, the duck bill is trapped between the grey plastic nuts and the 2.5bar MAP sensor is plugged into the end of the hose.



The black dot is the pressure bleed down hole and the cloth stuffed inside is my attempt at a damper.



Pink line is the MAP sensor, Blue RPM and Red throttle.

This is the first time the engine was responsive to shutting and opening the throttle.

Of course the old fuelling map is ratshit now and will need re mapping but the throttling results with the MAP sensor are very encouraging.

Things are looking up, maybe even possible............. EFI whoop whooop.

[Sandokan]

Hi all,

I was thinking that to create a fuelmap for a twostroke , would it be possible to somehow "record" an exhaust harmonic frequency in conjunction with a tps an wideband lambda on a carburated twostroke?

Just a thought but probably worth something for the fi guys

Sander

[Niels Abildgaard]

Put a Piezo thing ring under one of the headstud nuts or between head and sparkplug and a very rude instant cylinder pressure signal can be had.
When piston is halfway down You will know if it fired or not.
And then: Who tried it allready and why does it not work?

[TZ350]

would it be possible to somehow "record" an exhaust harmonic frequency in conjunction with a tps an wideband lambda on a carburated twostroke?

Good idea Sandokan, I didn't record the exhaust but I guess its possible. I did use the wideband lambda and carb to get an idea of what the fuel map should look like.

Put a Piezo thing ring under one of the headstud nuts or between head and sparkplug and a very rude instant cylinder pressure signal can be had.
When piston is halfway down You will know if it fired or not. And then: Who tried it already and why does it not work?

Another good idea, thanks Niels. It could well work, unfortunately my Ecotrons software does not have a suitable input available, it is short on alternative inputs. But it does expect a MAP sensor which is why I am trying to see what can be done with that.

Unlike some other EFI systems the Ecotrons software does not allow for a binary input that switches between two maps. But there is a place for an analog input from the MAP sensor to influence the Ecotrons software to adjust the predicted fueling requirements from the Alpha-N map at any TPS/RPM.

The Ecotrons software adjusts the injector pulse width according to the Alpha-N map and input from the MAP sensor. It is how to make use of that relationship for fuel injecting a two stroke which is the trick I am trying to learn.

[Nath88]

Unlike some other EFI systems the Ecotrons software does not allow for a binary input that switches between two maps. But there is a place for an analog input from the MAP sensor to influence the Ecotrons software to adjust the predicted fueling requirements from the Alpha-N map at any TPS/RPM.

I was just about to recommend using the map switch I tried it out this weekend, its not dialled yet, but it's the best so far, I can roll along at 8500rpm and open and close the throttle as fast or slow as I like and it always responds. I will tune the main map by lambda feedback (it's pretty much done using values from before), and the misfire map by holding the engine at a load point, then holding the kill switch for a second or two, then release and judge the response when it comes back on as rich or lean, it should be instant and clean like a carb.
The map switches when the peak pressure between 85 crank degrees and 125 crank degrees, measured at the PV vent (with an adjustable bleed to atmosphere) reaches 102kpa, atmosphere is 101kpa here.
Means I'm confined to riding at sea level until I sort out a better implementation. Hoping the piezo pulse sensor will be the ticket, since it doesn't care about absolute values, If it works I'll make a bunch of them.

I think the piezo on the cylinder head idea could work, if the signal is not too noisy.

[TZ350]

Smoothed the MAP sensor reading by adding some volume by replacing the MAP sensor hose with a small chamber.



MAP sensor Yellow line. Interesting that the line on the left as the engine is still winding down and zero throttle is higher than the MAP pressure line at WOT and as the RPM starts to rise again.

[peewee]

Just squirt some petrol into carb before trying to start.
I´m using a 'squirt bottle' as the big guys in dragracing, supersimple!

Always starting on 1st or 2nd kick when cold with that. =)
I have started it down to about 15f with no hassle.

Get a richer needle!
If just adding more and more powerjets i figure the lowspeed system still is very lean?
My jetting on 211cc and ~75.5hp at the crank is in Keihin sizes: 110 pilot, 265 main, homemade powerjet opened about 1/4-1/3 turn.
Starting with 1/4, and when engine is hot i turn it more open to about 1/3.(i figure it starts to free up the containing oxygen, like 'nitro light' effect)
Still when engine is really really hot after a hard dynosession with about 10 pulls in a row it tends to runaway on idle, i might need 120-125 in pilot when hot.
But it is so much harder to get it to warm up properly with bigger than 110.

This with only methanol fuel.
If i were about to run say 20% nitro i would increase pilot a lot, just to make sure engine won´t runaway.

Rgds.

what do you guys think of this idea. for starting the engine cold I can drill a hole and tap threads in the carb on the engine side of the slide and install this nipple and attach a small hose so petrol or ether can be squirted in. of course I would put a rubber cap on the nipple before attempting to start the engine. check out photo to see what I meen . other wise I don't know how to get this bugger fired up

squirting petrol or any other starting fluid on the back side of the slide will be time consuming as the seat, body panels and sub frame with airbox would need removed. spraying ether directly to the airfilter may wash away the oil and allow in dirt

[Grumph]

You're not the first to strike this problem. A guy here had a 600 Suzuki GSX racebike - late 80's style with full bodywork. Ran it on methanol and had a lot of problems starting it. Finished up with a plastic tube with a cork in it, up beside the steering head. Tube ran to the airbox, so it was pull the cork, squirt starter fluid (ether) down the tube, replace cork, start bike....A practical solution I thought.

[husaberg]

Wob was it the TZ g pipes you wanted a drawing of ages ago.