85hp Enduro 2stroke No Spark - Peak voltage testing help??

[Drifter1]

Hello,
I am trying to trouble shoot this issue and need some help as it’s my first time working on ignition system.
Engine was running perfect and then a few times cut out. Eventually it would not start again.
There is no spark getting to all three coils.
I did the below test following a service manual and then replaced the CDI as recommended. This did not fix the problem now I am stumped. Now wandering if o have done something wrong with the testing method or setting on the multimeter.
Any one tell me what I am doing wrong?? Or where to look next?

2017 85hp Enduro 2 Stroke
I am in Central America.
Tests done with Peak reading DVA adapter and meter.

Charger coil (Stator/Set de Bobinas)
Unloaded / Cranking
Red - blue - 220vDC 12-30VAC 63 ohm
Red - brown - 75vDC 1vAC 654 ohm
(Manual says test DC but this confused me as I thought it should be providing AC to the CDI??? So I provide both readings with meter set to DC and AC)

Pulser coil
Unloaded / Cranking
Red-Yel - 8.7vDC 332ohm
Black Green - 7.8vDC 322ohm

CDI to Coils
Loaded / Cranking (Spark plug caps off)
Cylinder 1 - 3v
Cylinder 2 - 3v
Cylinder 3 - 3v

Changed and charged battery
Cleaned and replaced all connections that looked corroded
Tested stop switch as per manual OK
Tested neutral switch as per Manual OK
Removed the pink and white cable connector to the CDI and tested CDI output to coils. No change.
Replaced CDI for new. No change.

[99yam40]

1st thing I see wrong is the manual should be giving minimum peak voltage reading, never heard of them giving maximum.
something screwy with that manual in my opinion.
next is I thought when loaded meant everything hooked up as it should be to run. so not sure why it says to pull the plug wires off of the plugs.
If you do not want the motor to fire up, pull the plugs out and ground them so they can still spark but not fire off a cylinder.
I have read that with nowhere for the spark to jump to it may build up too much voltage and it will jump anywhere it can( meaning inside the coils possibly damaging them)

hopefully someone with more knowledge of your motor will see your post and give you more info.
by the way was that a service manual from Yamaha or an aftermarket?

[Drifter1]

Thanks for commenting. I found the manual online for free. As these aren’t sold in the US it was a bit difficult to find one. It seems legit enough but I’m not sure. I’m not sure what you read, but I read it as those being minimum voltages and both charge and pulser coil were over spec and CDI to ignition coils were under spec this is why I changed CDI but it didn’t solve the issue.

[99yam40]

the only thing I know that would kill spark out of the CDI with good inputs would be the Kill switch , its wiring grounding on the way to the CDI, or the CDI itself.
might disconnect the wires from CDI to the coils and then test the peak voltage out of the CDI to make sure the coils are not dragging the voltage down,
but I do not see how all 3 would go bad at the same time.

When I bought my C40 I was doing a lot of testing, and Rodbolt 17 ( a master tech) told me over voltage was OK just not undervoltage.

I do not see how you could get peak voltage reading on a motor at 1500 and 3500 RPM with the plug wires disconnected

[boscoe99]

Hello,
I am trying to trouble shoot this issue and need some help as it’s my first time working on ignition system.
Engine was running perfect and then a few times cut out. Eventually it would not start again.
There is no spark getting to all three coils.
I did the below test following a service manual and then replaced the CDI as recommended. This did not fix the problem now I am stumped. Now wandering if o have done something wrong with the testing method or setting on the multimeter.
Any one tell me what I am doing wrong?? Or where to look next?

2017 85hp Enduro 2 Stroke
I am in Central America.
Tests done with Peak reading DVA adapter and meter.

Charger coil (Stator/Set de Bobinas)
Unloaded / Cranking
Red - blue - 220vDC 12-30VAC 63 ohm
Red - brown - 75vDC 1vAC 654 ohm
(Manual says test DC but this confused me as I thought it should be providing AC to the CDI??? So I provide both readings with meter set to DC and AC) AC voltage is created by the charge coil but when using a peak reading adapter the meter is set on DC volts. Your voltages exceed the minimums published in the SM you have provided.

Pulser coil
Unloaded / Cranking
Red-Yel - 8.7vDC 332ohm
Black Green - 7.8vDC 322ohm

Your voltages appear good but the SM is showing more wires to be tested.

CDI to Coils
Loaded / Cranking (Spark plug caps off)
Cylinder 1 - 3v
Cylinder 2 - 3v
Cylinder 3 - 3v

These voltage are well below the minimum specifications. Far far off. 3 volts to a coil that is supposed to be seeing 130 plus volts is not going to cause a spark plug to spark.

Changed and charged battery
Cleaned and replaced all connections that looked corroded
Tested stop switch as per manual OK
Tested neutral switch as per Manual OK
Removed the pink and white cable connector to the CDI and tested CDI output to coils. No change.
Replaced CDI for new. No change.

Find the white wire at the CDI box. Disconnect it. Then see if the motor starts and runs.

[boscoe99]

Thanks for commenting. I found the manual online for free. As these aren’t sold in the US it was a bit difficult to find one. It seems legit enough but I’m not sure. I’m not sure what you read, but I read it as those being minimum voltages and both charge and pulser coil were over spec and CDI to ignition coils were under spec this is why I changed CDI but it didn’t solve the issue.

What is the complete model and engine ID?

[boscoe99]

Thanks for commenting. I found the manual online for free. As these aren’t sold in the US it was a bit difficult to find one. It seems legit enough but I’m not sure. I’m not sure what you read, but I read it as those being minimum voltages and both charge and pulser coil were over spec and CDI to ignition coils were under spec this is why I changed CDI but it didn’t solve the issue.

Voltages given are minimums. No such thing as too much.

If the white wire to the CDI is grounded then the CDI won't be providing the ignition coils with the voltage that the charge coil provided to the CDI.

The stop switch can be just fine. But if the white wire gets chaffed to a ground then that is the same as the switch being closed. No sparky.

[Drifter1]

Thanks for the comments much appreciated.

I don’t have exact model on me now.

I tested the kill switch at the coupler inside engine cowling as per manual. OK

I removed the connector with white and pink cables going into the CDI which I believe are kill switch and thermoswitch. No change. I believe this eliminates both of them from the equation?

i have not tested the individual coils as you say it’s unlikely all three would go so I assumed due to the fact none of the three are getting spark it would not be them that’s the problem but I guess at this stage I should check each one.

Regarding the pulser coil. I don’t see the other wires that should be tested. Could you point me in the right direction?

Thanks a lot for the info and ideas.

[99yam40]

that motor probably has 2 pulser coils, strange that they unloaded peak voltage readings are different, but not much different.

I would be taking loaded and unloaded reading on all of the coils.
do you still have good voltage into the CDI when you have very low voltage to the ignition coils?
You did unloaded to charge and pulser coils but only loaded out of the CDI to the ignition coils.

Something to think about, if the CDI does not get the proper signals to tell it when to fire the plugs they will not fire.

My C40 has 3 pulser coils one for each cylinder.
yours probably like the 3 cylinder 90 only has 2.

I am not sure how yours fires that 3rd cylinder, maybe a crank position sensor or something else involved.
Boscoe needs you motor info to look up info.
so get that and post it.

and also give info on your service manual just to make sure it is correct one for your motor.

I still cannot believe it says what it does about replacing the CDI if the Charge coil voltage is too high.
Edit: Rereading that again, I guess it was stating that if you have good voltage into the CDI but low coming out the CDI should be replaced( and that is what you did)

[boscoe99]

The diagram that you posted shows 4 wire pairs to be tested for the pulser coils.

What are the markings that are on the CDI?

Can you post a photo of the wires that connect to the CDI?

[boscoe99]

I believe the manual is saying that if the CDI does not have sufficient output voltage then check the voltage to the CDI. And if the voltage to the CDI is above the minimum specification (meaning the input is good) then replace the CDI.

Same with an R/R. If the R/R output is no good, check the R/R input. If the R/R input is bad, fix the R/R input. If the R/R input is good then replace the R/R.

[99yam40]

I looked at the wire colors also he posted.
I have a feeling the W/R to W/Y in manual is what he called Red to Yellow Ect.
so just 2 wires from each pulser coil

[ausnoelm]

Just trying to piece this together, I “think” you have jumped over the cut out wires being possibly grounded, you tested the switch, but that’s NOT checking the actual wiring harness being chaffed/pinched and grounded “somewhere” even disconnecting the switch does not test for grounding. Your voltage tests are a bit vague, your original fault of cutting out, then no start, indicates a bad wiring fault

[boscoe99]

I still cannot believe it says what it does about replacing the CDI if the Charge coil voltage is too high.
Edit: Rereading that again, I guess it was stating that if you have good voltage into the CDI but low coming out the CDI should be replaced( and that is what you did)

Been out walking and trying to think of a better way to say what the SM is trying to convey.

I like to use water as an analogy to electricity. So let's say a pump needs to be provided with 50 gallons of water a minute at 5 psi to be able to pump out 35 gallons per minute at 100 psi.

If the pump is not putting out 35 gallons per minute then something is wrong. But what is it?

If the pump is not getting the water it needs (50 gpm at 5 psi) then fix the water supply. But if the pump is getting more water than it needs 50 plus gpm at 5 psi) , and the pump is not putting out 35 gpm at 100 psi then change the pump.

[boscoe99]

Just trying to piece this together, I “think” you have jumped over the cut out wires being possibly grounded, you tested the switch, but that’s NOT checking the actual wiring harness being chaffed/pinched and grounded “somewhere” even disconnecting the switch does not test for grounding. Your voltage tests are a bit vague, your original fault of cutting out, then no start, indicates a bad wiring fault

This is the modus operandi for all too many.

Folks must like to shotgun an approach to a problem. They almost never ask how a system works. And without knowing some systems are all but impossible to fix.