Hey guys, been a while since I have posted but I have another stumper that I hope you all may be able to help with.

A guy brought me this bike to Dyno Tune so we ordered him a jet kit and proceeded to tune the bike. The Air/Fuel ratio seemed to pretty much stay the same no matter how much fuel I added or took away. Also something odd that I have never seen...the plugs were white indicating a lean mixture but my AFR was reading nearly 11:1(very rich). My gears got to turning and I thought that this is most likely ignition. The bike is putting down roughly 35 hp. They are roughly 55 hp out of the box. So I am running nearly 20hp shy of factory numbers.

I have a couple of waveforms that I have saved and will attach for you guys to check out. I normally dont like to jump to the most expensive part to replace but I think it may be a possible CDI box failure.

I started with the scope on the secondary side of the coil and have worked my way backwards towards the CDI box. The coils all ohm out within spec on the primary and secondary side according to the service manual. (.2-.5ohms primary side) (35K ohms on the secondary side)

The trigger coils also fall into spec at 523 & 528 ohms.

All wires from the CDI to the coils have been check and show good continuity and have no shorts to ground.

So my thought is that if I have good information/signal going into the CDI box and getting poor signal out...seems like a CDI?

The attached file with the primary coil voltage and secondary voltage are both under load and both seem bad to me. (Don't look like good waveforms) Front and rear coils are almost identical which also points to the CDI because my thought is...what are the odds of two coils failing at the same time?? :-/

Still not a master at the scope which is why I am asking what you guys think!  :)

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Attached is the dyno sheet.

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Hi, first of all that it is not CDI ignition but Transistorized ignition. You can tell that from your capture. I believe you may have used the wrong probe setting for you secondary leads as the voltage is way too high. Do you have the colored leads and did you by chance select the "black secondary probe" setting? I personally do not see a problem with coil output, primary looks good. The only thing I see is the secondary is suggesting to have a lean condition because of the sloping up of the burn line. Are you using a 4 gas analyzer or a wideband to determing afr? Is 11-1 at wide open top rpm?  If using the 4 gas what is your 02, co and co2 readings. Down that amount of hp I would think would require a dead hole or some major mechanical problems. If you want a quick and dirty test for afr problems stick it on the dyno and do a lean/rich test quickly by opening up the airbox lid slightly (lean) and partially duct tapping off the intake snorkel (rich). Only do enough to make a small change in power output. If it goes up in one of the tests, try slightly more. If it goes up again you for sure have found at least one problem. Can you do an in cylinder compression test? Can you post the Dyno graph?

James H wrote on Oct 20^th, 2017 at 3:11pm:

Hi, first of all that it is not CDI ignition but Transistorized ignition. You can tell that from your capture. I believe you may have used the wrong probe setting for you secondary leads as the voltage is way too high. Do you have the colored leads and did you by chance select the "black secondary probe" setting? I personally do not see a problem with coil output, primary looks good. The only thing I see is the secondary is suggesting to have a lean condition because of the sloping up of the burn line. Are you using a 4 gas analyzer or a wideband to determing afr? Is 11-1 at wide open top rpm?  If using the 4 gas what is your 02, co and co2 readings. Down that amount of hp I would think would require a dead hole or some major mechanical problems. If you want a quick and dirty test for afr problems stick it on the dyno and do a lean/rich test quickly by opening up the airbox lid slightly (lean) and partially duct tapping off the intake snorkel (rich). Only do enough to make a small change in power output. If it goes up in one of the tests, try slightly more. If it goes up again you for sure have found at least one problem. Can you do an in cylinder compression test? Can you post the Dyno graph?

[smiley=thumbsup.gif]  Nice!

James H wrote on Oct 20^th, 2017 at 3:11pm:

Do you have the colored leads and did you by chance select the "black secondary probe" setting?

That is exactly what he did.


Russ,

Use the colored secondary probe from your probe library section.  if you have nothing in the library section, install the Autonerdz PicoScope add-on.

You are correct it is a TCI rather than a CDI. Tom and James, you were definitely right the settings were wrong. I have changed them to the colored wire secondaries and re run the test. See attached file.

Mechanical problems are fairly ruled out. Compression is even on both cylinders at 150. We have also tried opening the air box and closing it off and other variations of varying the fuel delivery which is why I started checking out ignition. Every combination of fuel change has had no effect on horsepower curve.

I wish I could get you the other information regarding the 4 gas but we are using a wide band o2 from our dyno. I do have a test gas that we use to check our sensors before we do any dyno tuning and both of my o2 sensors check out and have also been swapped around to make sure of an accurate reading.

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RedlinePowersports wrote on Oct 21^st, 2017 at 6:45am:

You are correct it is a TCI rather than a CDI. Tom and James, you were definitely right the settings were wrong. I have changed them to the colored wire secondaries and re run the test. See attached file.

Much better! Do you have other coils you could sway onto this?

Unfortunately no, I have some other coils laying around but not a direct part number replacement. Do you see a problem with swapping in a different coil from a different bike? If I did, what requirements would I look for in a coil so to not damage the TCI?

Just noticed in your first post you said primary resistance of the coils is .2 to .5 ?. Primary side of the coils should be 2 to 2.5 ohms. Any non CDI (they always have very low pri resistance - read high amperage) coil off any bike will work.
When did the problem start? Since you put in a jet kit? After the customer did some modification? Did it happen suddenly or deteriorated over time. Is it consistent? How much mileage? This will help with a diagnostic direction.

Your peak torque looks about right at 3000 rpm but just falls off too quick. In my opinion I would think a air flow or air fuel ratio problem as an ignition problem I would think would show up at peak torque. Do you have a plugged carb slide vent preventing them from opening?

The problem has been there since we got the bike in. We did a baseline for him a few weeks ago and saw the low torque/hp curve. Since the customer has "bobbed" the bike and changed exhaust we naturally assumed the fuel air was wrong so we recommended a tune.

After tuning for some time and seeing very little change on the graph we started troubleshooting the problem. The problem was there before the jet kit and has remained unchanged since the jet kit was installed.

Bike has 27,208 miles. As far as I can tell the bike has had the problem for some time. The customer brought it in originally for a tune saying that he felt that the bike should have more power. He couldn't be more right.  :P

Both carb slide are free to move and I have visually confirmed this with the intake boots off while running on the dyno.

If I am not mistaken, isn't the peak voltage on the secondary low? Its right around 4-7k volts. Aren't most coils upwards of 40k volts?

RedlinePowersports wrote on Oct 21^st, 2017 at 10:29am:

The problem has been there since we got the bike in. We did a baseline for him a few weeks ago and saw the low torque/hp curve.

Smart move. We do the same here and it has saved a lot of stress when dealing with a customer. Showing them what they really have vs. what they think they have works wonders!


RedlinePowersports wrote on Oct 21^st, 2017 at 10:29am:

Since the customer has "bobbed" the bike and changed exhaust we naturally assumed the fuel air was wrong so we recommended a tune.

This has come up a lot here. Someone thinks a tune is the issue when it's something else.


RedlinePowersports wrote on Oct 21^st, 2017 at 10:29am:

After tuning for some time and seeing very little change on the graph we started troubleshooting the problem. The problem was there before the jet kit and has remained unchanged since the jet kit was installed.

We have a saying if you add 10% fuel, take away fuel 10%, add  10 to 15 degrees lead ignition timing and take away 10 to 15 degrees lead ignition timing and little or no response it's not the tune.


RedlinePowersports wrote on Oct 21^st, 2017 at 10:29am:

Bike has 27,208 miles. As far as I can tell the bike has had the problem for some time. The customer brought it in originally for a tune saying that he felt that the bike should have more power. He couldn't be more right.  :P Both carb slide are free to move and I have visually confirmed this with the intake boots off while running on the dyno.

[smiley=thumbsup.gif]


RedlinePowersports wrote on Oct 21^st, 2017 at 10:29am:

If I am not mistaken, isn't the peak voltage on the secondary low? Its right around 4-7k volts. Aren't most coils upwards of 40k volts?

You will only see the coil output that high when there is an open circuit either because of an issue or you made it one by pulling a plug wire off and making a larger gap.

I have also noticed on your primary voltages you are reading negative. Just how are you hooking up your leads?

Just putting the curved clamp on the plug wire and the ground wire to the chassis of the bike.

RedlinePowersports wrote on Oct 21^st, 2017 at 12:00pm:

Just putting the curved clamp on the plug wire and the ground wire to the chassis of the bike.

Tell us how you have the primary traced hooked up please.

RedlinePowersports wrote on Oct 20^th, 2017 at 1:46pm:

the plugs were white indicating a lean mixture but my AFR was reading nearly 11:1(very rich).

Good thread, but one quesiton?, how is the AfR determined, is this with a scanner or what?  11/1 verses White plug, someone is not telling the truth and it is not the plug, don't need a Pico or scanner for that, but suppose timing could do that.  Is this unit injected or old school float ect?

After liestening to James, hate too say too much and sound stupid, he is all over this, James, as Spence stated I second Nice.

Stitch

Just for fun, what are we using for fuel, is it any good????, or how much Alcohol??????? 10//1 is about what it takes for that crap, not you drinking LOL.

Stitch

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

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The AFR sample is being taken with our DynoJet 250i Dyno.

As stated before two different o2 sensors have been checked and verified that they are working properly. When I put the test gas to each sensor (Control gas specified at 13.2 AFR) the sensors both read 13.2 which shows that the o2 sensor is working as it should. The white on the plug is why I suspected a problem other than fuel. I have richened the mix up so high that I had black coming out of the pipe and the o2 still read 11.2 and the plug was still white.

As for the primary hookup, I have the regular two wire leads hooked up to the ground wire (Black spade connector) at the coil as well as the positive side of the coil (blue/yellow wire ) at the coil coming from the TCI and I also did this same set up at the TCI to rule our wiring in the bike. I have the same setup on the other coil as well.

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  ::)

Figured out how to post the image. The circled parts are what I was referencing in the previous post.

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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

RedlinePowersports wrote on Oct 23^rd, 2017 at 12:25pm:

nd the o2 still read 11.2 and the plug was still white.

A thought. On cars we get a lean burn code all the time, meaning 02 is seeing air that has not been used in combustion, but blowing black smoke which we all not is not a lean burn, old school or new school.

This usually happens when we have a leak in the exhaust after combution, but ahead of the 02. You could then have black smoke still have lean 02 readings, and no matter how much fuel you add it will still code lean, when we know it looks like and old school stuck float, black everywhere.................??? on exhaust gaskets.

NOW, that does not explain the white plugs 4 sure, as Bill Clinton once said, "I FEEL YOUR PAIN'

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.

I agree with Larry, burn time is low and there appears to be is a lot of hash from turbulence. I also agree with Spence as obviously can't be a fuel problem if no change when going rich or lean. Can you put a low amp probe on the primary of the coils and get a capture? Also, can you capture a max output on the coils by using a spark tester set with a nice wide gap? What do the pipes look like that this guy put on? Baffles? Also, hate to ask but we do know compression, leakdown is healthy - right?

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

I also agree with Spence as obviously can't be a fuel problem if no change when going rich or lean.

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

RedlinePowersports wrote on Oct 24^th, 2017 at 9:53am:

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

Redline, a thought here. What RPM was this runnning @ during test.  I have noticed every other ignition appears too me to be waste fire as not much of a signature as nothing in the jug to resist.

This stated, what is the strategy of this model, I.E. meaning the yellow trace is primary from the other jug and appears it fires before the other jug., is this normal or are do we have a problem there??

I know Harley I think fires offset, just asking here??? Would now really like too see a compression wave, don't know if you have the WPS 500, but what James asked for amp on coil would be sweet too. As far as compression the wave would produce that also.

StitchB

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

James H wrote on Oct 24th, 2017 at 3:42pm: I also agree with Spence as obviously can't be a fuel problem if no change when going rich or lean. James, under no circumstance, do you ever agree with Spence, LOL, StitchB

[smiley=rolleyes.gif]

Thanks for the input guys. I will run the suggested tests and post them.

I will also see if I can upload pictures of the pipes/baffle system.

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??

Auto Sparky,, glad to have the input.

Talking with James whom bought a Pico, and Redline here we have managed to get Spence/Mick involved over time as the motorcycle guys probably don't get a lot of input on this tool, And I not being an actual 9/5 shop wrench study it a lot, and also use it, but not with the frequency of a lot of others, so the input from anybody on the auto side is really great.

Yes all of us would like to see compression ect, but need to start somewhere. And as I have stated I have no idea what a know good system with this ignition looks like. As stated my KLR coil is fed 120Volts AC , so the dynamics of the images even my instructor had never seen, so all new ground for some of us. This is not a KLR, but might be different that anything we are used too.

Stay tuned, thanks for the input

StichB

Auto Sparky,

Just viewed your location, see NZ, welcome.

Larry

Okay guys, Sorry it took me a while to get back on this. Been a little crazy around here. I took a new capture that I think I may have found something. Not sure though.

Check out the capture and let me know what you think. The capture is done fully on the front cylinder. Two secondaries because each cylinder has two spark plugs. The red and blue leads are secondary ignition. They should be firing at the same time due to firing off the same coil. The green lead is primary voltage and the yellow lead is primary current as you guys requested.

If you zoom in on the primary current (yellow lead) halfway up the arc you will see a bumble in the current draw. I think this may be part or all of the problem. Not 100% on what it means but I would have to believe that the amperage draw should be a smooth arc and not have a varying line in it. This, to me, could be why the secondary KV numbers and burn time are low.

What do you all think? I am happy to send any more info you guys want!

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Here is the current draw issue that I was referring to in the previous post.

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Another view but zoomed in on one waveform.  Seems like a pretty big dip in amperage.

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Yeah, doesn't look right to me from my limited experience. The coil turn off doesn't either but I have seen where they do not completely fall to ground straight down, just not that bad. Can you do the other coil to see if its the same?

Sure, will do. Stand by.

Rear cylinder current draw. Definitely different!

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Zoomed out a bit on the rear cyl to capture a few waveforms in a row.

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Here is the full file if you guys want to compare to the front cylinder.

Let me know if there are any other tests you think I should run.

I definitely see a difference here between the current from front to rear cylinders.

Could this be a bad TCI not switching on and off properly? The pulse or trigger coil waveforms looked good to me going into the TCI.

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Does TCI stand for something that is controlling the ignition coil primary?

Transistor Controlled Ignition

RedlinePowersports wrote on Nov 2^nd, 2017 at 12:55pm:

Transistor Controlled Ignition

That's what I thought but hate to assume.

So I spent some time today and I (believe it or not) had a matching coil laying around the shop that is the same as the ones that are in the bike. But only one :/

So I swapped out the front coil with this one from the shop, I also discovered that I had the current clamp on the wire backwards. I totally spaced and forgot that it has an orientation.

Attached is the new waveforms and the current looks much different! Still not making any more horsepower tho :/

After this post I will post the rear cylinder for comparison. The rear cylinder amperage draw looks slightly different. The rear cylinder is the coil I did NOT change. Just want everyone to know which one was changed and which was not.

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Attached is the rear cylinder data. Like I said the current seems different at the tail end of each pulse or turn on.

Please let me know if this helps! I'm running out of ideas!

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Redline, Burn times with these look more normal, and noticed RPM seems to be around 1800,, is that a normal RPM for a twin?, Idon't know, sounds high, usually indicative of a lean burn. Have we ran this unit with exhaust off, ect.

Noted fire time about 1.3 MS, and the other is IMO, waste fire as only about half that as there is nothing in that hole.

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autosparky wrote on Oct 26^th, 2017 at 9:32pm:

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

Okay, busy looking @ burn time ect, what is the vacuum on this engine?, can we do a COMP wave form?

Ye tweaked the exhaust, have no idea the ramifications on that, but can this engine breath???

Yeah the burn time did seem to improve, not sure why though. It seems better on both cylinders even though I only changed one coil.

The RPM is 1800 because I have been doing these pulls on the dyno under load. Idle does not seem to be the issue. The bike is 21 hp short of stock so I thought that under load would be the best place to test.

As far as I know it can breathe. I went back to basics last night and checked compression again. Both cylinders even at 150 psi. I also performed a cylinder leakdown test. Front cylinder 5% leakage from the crank case and the rear cyl 2% leakdown from the crank case. In the motorcycle world that would qualify as a tight engine and in theory it should make power.

I would like to do a compression waveform but I do no have the tool to do so :/

Hard to tell for sure if the Current ramp is better with that coil as you had it inverted and the top is cut off because of your scaling. It does appear that the front coil is defective looking at the earlier waveform thou. In my opinion I do not think you have a control problem (TCI). If the power is still bad and it was me, I'd be looking elsewhere.

Well guys we got it figured out!

It took some hours last night but we got the horsepower back. Some of this was me being a novice to the scope but the scope was able to confirm a lot of suspicions I was having.

After I got the scope dialed in and hooked up the current clamp correctly  :P I was able to prove that everything on the ignition system was working. I also was able to prove that the bike was advancing timing like it should. (For a little while I was thinking that maybe the TCI was not advancing timing which would definitely cause hp loss.)

I learned alot this time around on the scope. I learned how to set things up that I never have before and I was able to use previous bikes to prove good signals on this bike.

Enough chit chat, I am sure you guys are wondering what did all this!
Like I said, we checked compression and leak down, couldn't have been fuel because no matter how much fuel we added or took away it would not change and spark, after much debate, was also working like it should! If I had the compression waveform tool, this would have gone much faster. The customer had made, or he had someone make them for him...a set of "custom" baffles for the exhaust that are apparently extremely restrictive! After all things that make an engine run properly checked out, all I could think was that it was something outside of the engine so I started to look at the exhaust and waaay up there was these baffles. Removed them and did another run. The bike sounded so much healthier and you could definitely feel the seat of the pants power.

This was a challenge and really one to log away in my brain for later! I really appreciate all your guys input! I will post the hp/torque graph for you guys to see and also the known good ignition waves.  :)

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Much better looking spark now that the cylinders can breathe!

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Zoomed in view

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NICE!!! Thanks for the update. Glad you have it fixed.   [smiley=thumbsup.gif]

RedlinePowersports wrote on Nov 4^th, 2017 at 6:44am:

Zoomed in view

For these after repairs did you move the amp clamp location and/or orientate it differently?

Better ask for a WPS kit for Christmas, if you had a kit, a restricted exhaust would of showed up.

But then again - easy to say, post mortem

Glad you got it sorted, been interesting reading

StitchB wrote on Nov 3^rd, 2017 at 6:27am:

Okay, busy looking @ burn time ect, what is the vacuum on this engine?, can we do a COMP wave form? Ye tweaked the exhaust, have no idea the ramifications on that, but can this engine breath???

Redline, good on you.

Yeah, if you had WPS would have seen the high pressure as the exaust valve opened.  But all that is hind sight, 20/20 and as always, it is.

New ignition captures also look great, now for posterity we know what a good one looks like for other times. The beauty of all this is forced you to hook up, unhook, ect and with that comes what I call muscle memory and the ability to hit it quicker next time, and there will be a next time.

Good job

StichB

autosparky wrote on Nov 5^th, 2017 at 12:03am:

Glad you got it sorted, been interesting reading

Auto Sparky, thanks for the input from the auto side along with Spence and Mick, without it the bikes don't have a lot of input, thanks.

StitchB