ESE's works engine tuner

[F5 Dave]

If you can get to the tube slide a section of nail in it in case you start to crush it. Leave a section of nail exposed for extraction.

[wobbly]

I have removed the PJ in that carb by clamping s piece of square steel in the vise, hold the PJ end square on the bar, and tap the body directly next to the pressed in ball.
The PJ tube and the ball easily came out doing this.

[wobbly]

Neels is still locked out - nothing has changed, the connection request times out.

[husaberg]

Neels is still locked out - nothing has changed, the connection request times out.

for clarity of the admins and mods
Neels is KB username Vannik
https://www.kiwibiker.co.nz/forums/m...p/34343-Vannik

[TZ350]

.


Suggestions needed.

My good old new triple exhaust port methanol burning Kawasaki F81M 250 is suffering a serious bout of rough running around 8,000rpm.

Not a problem with the single exhaust port cylinder but a real issue with the tripple.

Things I have tried:-
Swapped out the Suzuki piston with the cutaway sides for a full skirt Wiseco one.
Reverted from my petrol/methanol carb setup back to a 100% methanol one.
Tried it with and without power jet.
Tried extreme richer and leaner main jetting. Jetting that makes best power also colours the plug and head. I would expect it to be clean.
Tried straight line ignition settings all the way from 5deg to 30deg BTDC. Over advanced can cause a patch of rough running.
Replaced the "R" retracted gap plug with a normal cold exposed tip one.
Tried plug gap settings from 010" to 030".
The coil is something that should be capable of throwing an arc across the room and welding heavy steel beams. Probably can create a spark underwater.
Both channels of the Race2 Ignitec discharge into the coil.
Checked that the Battery and generator can supply the ignitions current draw. About 4A at 10,000rpm.

Things that may be a problem:-
The scavenging stream is blowing the spark out.
The plug is slightly offset in the head and should be central.
Try it on petrol only. Although I want the methanol for cooling.

This was not an issue with the single exhaust port cylinder. The triple exhaust unit runs and sounds much better at 10,000 rpm than the single did.

Both my CHT and EGT gauges have chosen to go on the blink so not much help there.

Ideas???

[husaberg]

.


Suggestions needed.

My good old new triple exhaust port methanol burning Kawasaki F81M 250 is suffering a serious bout of rough running around 8,000rpm.

Not a problem with the single exhaust port cylinder but a real issue with the tripple.

Things I have tried:-
Swapped out the Suzuki piston with the cutaway sides for a full skirt Wiseco one.
Reverted from my petrol/methanol carb setup back to a 100% methanol one.
Tried it with and without power jet.
Tried extreme richer and leaner main jetting. Jetting that makes best power also colours the plug and head. I would expect it to be clean.
Tried straight line ignition settings all the way from 5deg to 30deg BTDC. Over advanced can cause a patch of rough running.
Replaced the "R" retracted gap plug with a normal cold exposed tip one.
Tried plug gap settings from 010" to 030".
The coil is something that should be capable of throwing an arc across the room and welding heavy steel beams. Probably can create a spark underwater.
Both channels of the Race2 Ignitec discharge into the coil.
Checked that the Battery and generator can supply the ignitions current draw. About 4A at 10,000rpm.

Things that may be a problem:-
The scavenging stream is blowing the spark out.
The plug is slightly offset in the head and should be central.
Try it on petrol only. Although I want the methanol for cooling.

This was not an issue with the single exhaust port cylinder. The triple exhaust unit runs and sounds much better at 10,000 rpm than the single did.

Both my CHT and EGT gauges have chosen to go on the blink so not much help there.

Ideas???

Put a longer carb bellmouth stack or lengthen the intake to see if it shifs the rpm where it turns to shit.
Quick and easy, if its not that move on.
https://www.kiwibiker.co.nz/forums/a...0&d=1322903746

[jonny quest]

TZ350, I just looked at your triple exhaust port shape.

I think you are having short circuit problems. This is showing an extreme case I've never seen, but it typically shows up in your area of dyno curve.

Fill in the bottom of those sub exhaust with epoxy, and hope you can make a quick dyno run before it blows out and see what happens

By bottom, I mean just the area that is inline with A port

[wobbly]

It sure as hell isnt the ignition system, but for the 10,000 th time, are you using a " proper " fine wire race plug that needs 1/2 the gap voltage to ionize.

First thing to look at is when the piston is at TDC, does the piston side cutaways expose a lump of Aux real estate , connecting the case to the Exhaust duct
thru the side port ducts. That will run like shit.
Its unlikely to be the A port short circuiting out the main port as it wasn't happening before - but sure you could be seeing vertical linking of the A port roof and the Aux floor if they are
separated by a very narrow septum width ( and this is why wide topped triangle Aux work so much better).

I have seen a similar thing happen if there is not a resistor cap and plug combination, or if the coil drive wires are not physically separated from any other in/out wires all the way
from the CDI plug end to the coil.
Also a possibility that the fueling is going haywire due to the much lower Blowdown residual pressure at TPO.
Remember that the mid range fuel curve is set by the needle/tube annulus area for low rpm/WOT.

[Frank S.]

To me this looks like a kind of resonance problem, because it only appears in a sharp band from about 8700 to 9700rpm. This is about 145 to160 Hz. Below and above this it runs fine.
Are there parts that can swing in resonance like carb, coil or something? Check the whole bike for loose parts.
Did you check the ignition timing with a strobo lamp at that rpm?

[ApolloMotoMoto]

.


Suggestions needed.

My good old new triple exhaust port methanol burning Kawasaki F81M 250 is suffering a serious bout of rough running around 8,000rpm.

Not a problem with the single exhaust port cylinder but a real issue with the tripple.

Things I have tried:-
Swapped out the Suzuki piston with the cutaway sides for a full skirt Wiseco one.
Reverted from my petrol/methanol carb setup back to a 100% methanol one.
Tried it with and without power jet.
Tried extreme richer and leaner main jetting. Jetting that makes best power also colours the plug and head. I would expect it to be clean.
Tried straight line ignition settings all the way from 5deg to 30deg BTDC. Over advanced can cause a patch of rough running.
Replaced the "R" retracted gap plug with a normal cold exposed tip one.
Tried plug gap settings from 010" to 030".
The coil is something that should be capable of throwing an arc across the room and welding heavy steel beams. Probably can create a spark underwater.
Both channels of the Race2 Ignitec discharge into the coil.
Checked that the Battery and generator can supply the ignitions current draw. About 4A at 10,000rpm.

Things that may be a problem:-
The scavenging stream is blowing the spark out.
The plug is slightly offset in the head and should be central.
Try it on petrol only. Although I want the methanol for cooling.

This was not an issue with the single exhaust port cylinder. The triple exhaust unit runs and sounds much better at 10,000 rpm than the single did.

Both my CHT and EGT gauges have chosen to go on the blink so not much help there.

Ideas???

"Tried extreme richer and leaner main jetting. Jetting that makes best power also colours the plug and head. I would expect it to be clean. "

Okay, thats a PURE combustion efficiency problem right there, previously you had complete combustion at these jetting settins, now you cant (coloring the plug and head at lambda values that previously burned "clean")

You also swept up and down the stoich lambda curve and nothing "fixed it".

What does this mean?

Even when you sweep to the stoich value that is the "easiest" to ignite for the fuel you are using, spark initiation is still failing.

With the fuel you are burning (hard to ignite alcohol fuels) AND the increased BMEP the engine is making with tripple exhaust port; high dynamic in-cylinder pressure at the moment of spark firing = higher required breakdown voltage AND dV/dt.

delta Voltage divided by delta Time

You can have all the voltage potential in the world with the capability of throwing the gap from here to the moon in a steady state, with UNLIMITED time to achieve breakdown....

But, that is not what Paschen says happens in a dynamic townsend regime that includes a "time-domain" function.

Literature (lab studies of plasma formation at internal combustion engine cylinder pressures/conditions) suggests that the required breakdown voltage to initiate the spark gap MUST BE ACHIEVED within 1-5 uSecs (0.001 - 0.005 seconds) or breakdown formation "LAG FACTORS" overcome the rising kV potential comming from the high voltage transient discharge from the CDI, through the COIL and into the spark gap.

This means:

If your systems RISE TIME for the first HIGH VOLTAGE transient pulse that is meant to "jump the gap" is TOO SLOW, it doesn't matter if you have 100,000 kV of open-circuit, open air POTENTIAL; you will fail to achieve breakdown for real in-cylinder conditions that maybe only need 20-30kV of VOLTAGE at the gap because you built your potential (rising rate) too slow.


Okay, thats problem number one.


Problem number two:

Lets assume you DID achieve breakdown, you DID jump the gap, and you DID establish a "nascent kernel".

Why is combustion proceeding so slowly and inneficiently around where the engine makes peak power/ peak cylinder pressure/ and probably peak MSV Turbulence....???

Turbulent conditions after the nascent kernel forms are "quenching" it before the CDI's discharg regime "catches up" and dumps the remaining energy stored in the discharge caps as lower volts and higher amps.

Once breakdown forms the kernel, the plasma channel becomes nearly superconductive; what was once an infinite resistance air-gap is now a highly conductive plasma channel, the volts required to sustain the arc are more like 800 - 1000V, so the remaining energy flows at higher relative current and lower relative volts.

This "post breakdown" current flow stabilizes the nascent kernel, grows its diameter, and delivers heat energy to this kernel.

It is CRITICALLY IMPORTANT that this post breakdown current is delivered in a window around 0-200 uSecs after breakdown occurs.

You dont want ALL of the current dumping in this quickly, but you MUST have SOME meaningful current delivered in this time window to stabilize the nascent kernel, or turbulence can ABSOLUTELY "blow out" the already established nascent kernel.

IDEALLY, you have a front-loaded current delivery window that dissipates a good margin in the first 200 uSecs, with a still meaningful "tail" that delivers energy over ~800 to 1,200 uSec total "spark energy delivery window".

None of this is necessary for a "simple" petrol burning engine at low to moderate BMEP and combustion chamber design "turbulence factors".

For an alcohol burning engine that wants RICH stoich values for best power, tuned to a high BMEP state, using a well optimized combustion chamber producing ...high... "turbulence factors", on the other hand:

This "time-domain" factor now becomes a lot more important to tune for in your ignitions discharge regime.


Attached is a document you have probably seen 100 times before from Frits, but it really does seem to match the condition you see on your dyno VERY well, especially the "saw tooth" pattern within the "power hole".



Now, you are using Wayne Wrights recommended CDI setup for this EXACT scenaio: jungle juice near impossible to light fuels at high engine BMEP with high turbulence head designs:

IgniTech 2 cylinder DC-CDI box with the outputs paralleled into one coil.

The questions I have are the same as Waynes:

1. Are you using the recommended NGK Race Plug?

Double fine-wire (laser welded fine-wire ground strap), Double rare-earth (irridium electrode, platinum ground strap)

NGK R7376 or equivalent.


2. Are you using the Crane Cams PS91 Ignition Coil Wayne ALSO says to run with this setup???


The "time domains" that I described above are mostly controlled by the natural resonant frequency of the CDI/Ignition Coil combination.

The capacitor(s) in the CDI and the "inductor" represented by the ignition coil (in addition to the resistive/inductive/capacitive contribution of the coils windings and the full circuits wiring loop) form an "LC Tank" equivalent circuit with a time-domain defined by the RLC of the combined components in the circuit loop.

This is one of the reasons Wayne recommends the Crane Cames PS91 coil specifically, when paired with the dual/parallel IgniTech DC-CDI setup, the natural resonant requency produced establishes a set of "discharge event time domains" that ACTUALLY WORK.


If you go arbitrarily trading out pieces of this setup, like for example, the ignition coil; for a different part with inductance/resistance/stray capacitance values that are much different than the Crane Cams PS91, then its entirely possible you skew the time domains into a region where you make PLENTY of power, just too late for it to actually mean anything to the spark kernel as its getting blasted by in-cylinder pressure and turbulence.



Wayne ALREADY HAS a setup that is KNOWN to work under these conditions.

If it IS a spark-loss condition, my FIRST recommendation would be to replicate Wayne's setup EXACTLY if you have not already done so.