Autonerdz forums

Okay, took a moment to look @ capture, James, or Redline, help me here. I have serious qestions about these captures, meaning no burn time exceed 500 miclro seconds, and in automotive anything less than 1 milisecond is broaching a missfire. 

Also noted 3 signatures line up secondary and primary except the green chanel, I have no answer for this. And that said the voltage spike on any ignition I know spikes, drops down, these have numerous rings before going to burn or maybe the rings are the burn in this type of system?, now I'm the student,  so have from my experience no baseline to say if it is good or bad, but strange.

That stated on my KLR the coil is 120volts AC, yes you read that right,  put your DVOM on it and weep. Does not get a diode, simply sends A.C. from stator to the coil which is about 1/4 the size of most as va=watts so if the voltage is 120 you don't need a large coid, just thought I insert this as bikes are strange creatures. That stated the firing signature on the secondary look like a screw, or AC equal above and below base line, then tapers off to nothing.

Guess I would like too see a compression wave form on this and see where our timing is actually at, and not on a scanner. My instructor Adam Robertson has a saying, scanners lie, Pico does not.

Stitch

I was noticing the same thing on the ignition waveform Stitch. I thought the burn time was a very small amount of time. Also if you zoom in on the secondary wave, the burn time duration has a bunch of voltage spikes where it should look like a nice "U" shape. Something to be concerned about?

I will try to capture it in a picture and post it but I am not sure I know how 

Okay, here is where I am.  There are bigger brighter minds than I on this, and would try and sequester more help from the automotive side, interpreting ignitions forms.

What troubles me........... is anytime you have primary, then shortly there after we have secondary. I don't know which jug here is which, but in screen capture we have a primary in yellow and then a delay for the seconday, whom ever in Red or blue channel. Then we have a primary in green and whom ever is directly above in Red or Blue, makes no sense too me.

All the noise you circled is IMO a bunch of turbulance from carbon, what ever, and I sure could be wrong but a butt load of noise.  What as previously stated is what I have been taught is burn time is like a rope which thusly turns a corner @ the point of burn. if the rope is high (long) I.E. lots of KV the there is less rope for the burn time, is how I can best put it.

In this system we have moderate KV, and literally no burn time, some of it 350U or 1/3 of a microsecond, unheard of in normal auto systems.

Here is what I propose, we need the wave form from a good running bike, as stated from cam and crank sensor.........???????????????what does a good one look like???, I have no idea as these images puzzle me, again might be normal on this system.

Thanks for the info on the AFR, sound sounds like you have spent some money and time on gear.  But too be blowing black smoke and not see it on the plug, (I'M STRUGGLING WITH THAT) but am sure you are telling the truth, but does defiy logic.

Now I'm wondering do we have one  primary firing both jugs, and one primary not firing either. In your screen print we have both jugs showing a burn, unless this bike is what I have been told is a twindle, meaning both fire @ same time and torque like a single, but are a twin.

StitchB

Stich the coil you are seeing is one coil with two spark plugs on one cylinder which is why they are firing so close together. They should be firing at the exact same time. This capture is of the front cylinder only on the secondary and the primary is showing both coils.

I can do another capture where they all match up...front and rear cylinders.

I agree, the black smoke/white plug have me baffled. The only thing I can think of is that the plug can not complete the burn and the fuel air charge just passes through the cylinder and out the tailpipe while making terrible horsepower.

James H wrote on Oct 24^th, 2017 at 3:42pm:


James, under no circumstance, do you ever agree with Spence, LOL, but yeah this thing has me baffled, again would like to find one somewhere and look @ a known good one, take care.

StitchB

StitchB wrote on Oct 25^th, 2017 at 6:31am:

Not sure if I'm any help, got no experience on small engines, so I'm reading with interest.

1)what does the engine sound like through the rev range? can you hear it mis-firing?


2)if playing with mixture rich/lean and playing with timing, does nothing then have you checked the compression and valve springs??