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

[99yam40]

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.

but you need to make sure all voltages are in spec not just some at the time the problem is showing up

[Drifter1]

Hi guys thanks for the comments. Sorry for the slow response.

Model: 85AETL
Serial number: 6881049179
Bought in Costa Rica

To confirm a few things:

Kill switch
Tested the switch itself OK
Tested the switch at the coupler inside the engine cowling. OK this eliminated the harness from switch to the engine.
Removed the two cable connector from the CDI which I believe is the input to the CDI for kill switch and Thermostat switch. Then tested the Peak voltage from CDI to ignition coils Loaded Cranking (with plug caps off as the manual says). No change remains 3-4V.
Am I missing something here?

Pulser coil test
There are four wires. Sorry for confusion I should have written as below instead of just the colour:
White with red stripe
White with yellow stripe
White with black stripe
White with green stripe
I tested as per manual and readings are in spec in first post:
WR-WY
WB-WG

Manual being used:
See attached pic of the front page of it.

Thanks for the comments much appreciated.

[Drifter1]

See attached pic of manual front page

[99yam40]

again,
You tested the charge and pulser coils unloaded, but not the output of the CDI to the ignition coils.
I would test them all unloaded .

and then test them all loaded to see if there is a difference in readings.

Hope Boscoe or someone can check to make sure that manual is a good one for your motor.

someone needs to explain the CDIs ability to fire 3 plugs with only 2 pulser coils,
I would think there has to be some other input to the CDI besides the charge coils and pulser coils, temperature ,and kill switch

[ausnoelm]

Most 3 cylinder Yamahas have a unique ignition system, cylinders 1&3 are produced by the pulser coils, cylinder 2 is “made up” by the crank position sensor, so……all three having no spark kind of changes the **** (providing this motor operates the same, I don’t know this model) once again, testing switches does NOT test/eliminate faulty/grounded wiring, it just tells you the switch is good! So far any testing has been quite random and confusing.

[99yam40]

If this motor has a crank position sensor, it has not been mentioned being tested .
This is why I asked about inputs to the CDI

As I said before my C40TLRX has 3 pulser coils, one for each of the 3 Cylinders.( not all 3 cylinder Yamahas are the same)

Drifter1, does the plug with the pink and white wires you disconnected go directly into the CDI?
Can you take a pic of those wires going into and coming out and post them up

[Drifter1]

The CDI has only the below inputs see pic attached.
Charger coil
Pulser coil
Kill switch
Thermo switch

Regarding the kill switch circuit.I hope this removes any doubt or confusion in what I am saying!! I just removed the white cable from the connector that plugs directly into the CDI and tested for continuity to ground.
Ignition key OFF - Grounded
Ignition key ON - Kill switch out - Grounded
Ignition key ON - Kill switch in (how you have it to run the engine) NOT Grounded.
This eliminates the whole circuit.

Regarding the testing Loaded or Unloaded. You are correct I tested Pulser and charge coils unloaded and CDI loaded only so I will test all Loaded and Unloaded and see if any interesting readings are found.

[boscoe99]

-------------------

[boscoe99]

Did the motor come from the factory set up for remote control or was it a tiller steered model that has been converted?

[Drifter1]

Hi Boscoe,
I believe from factory as remote control but could not confirm 100% that the dealer who sold it did not convert it.
This is Central America so anything is possible!!

[99yam40]

Hi Boscoe,
I believe from factory as remote control but could not confirm 100% that the dealer who sold it did not convert it.
This is Central America so anything is possible!!

so you bought this new in 2017?
or at least the 1st owner of this new motor?

[Drifter1]

so you bought this new in 2017?
or at least the 1st owner of this new motor?

Yes it was bought new in 2017 from a local dealer.
I have seen the invoice for it and can confirm.

[boscoe99]

I be flummoxed. Two CDI's having the exact same issue. Both having good inputs but both having nil outputs.

Only thing I would now try is to remove the coupler for the thermoswitch/kill switch wires to the CDI. If this has not already been done. My thinking being that perhaps something is amiss at the coupler.

Maybe remove and reattach the CDI ground wire at the block.

[boscoe99]

Maybe back probe the charge coil wires on the CDI side to see if spec voltage is seen there.

[99yam40]

Maybe back probe the charge coil wires on the CDI side to see if spec voltage is seen there.

that would be getting peak voltage readings loaded from the charge and pulser coils , correct?
that is what he said he would be doing soon, hopefully