V4 130 erratic CDI voltage

[YamV4130]

I was trying to measure the voltage output from the CDI to the ignition coils for my V4. I have build a DVA that works (checked against 230VAC 50HZ =320VDC peak), but the ignition coil voltage was erratic between 10 and 150V.
I then set the multi-meter on AC and measured steady 0.32VAC @750rpm. There was no difference @1500rpm.

The motor is a V4 130BETO 306706 93 model. I found a SM that specify the resistance the the different parts, and all coils check just fine. I have not measured the resistance in the CDI circuit. I am using the voltage listed in a newer SM (6E5-28197-Z9-C1).

What is the correct output voltage for this CDI, and why is the voltage so erratic? The test was done on 3 of 4 cylinders.

[boscoe99]

Output voltage is noted below.

Have not any idea why voltages would be so erratic.
z130cdi.jpg

[99yam40]

how are you measuring the peak voltages on this motor while it is running?
do you have a special harness to hook into the wiring with it still going to the coils?
Search for CDI troubleshooting if you do not have a service manual

[YamV4130]

how are you measuring the peak voltages on this motor while it is running?
do you have a special harness to hook into the wiring with it still going to the coils?
Search for CDI troubleshooting if you do not have a service manual

I am measuring one coil while idling the motor, using a DVA and multimeter. I have the SM, but the peak voltage is not included. Got in now.
The erratic values are still a mystery.

[99yam40]

SM should have all of the specs loaded and unloaded peak voltages

loaded should be with all wires hooked up and tied to DVA with motor running
did you check the input and outputs of the CDI?

[YamV4130]

SM should have all of the specs loaded and unloaded peak voltages

loaded should be with all wires hooked up and tied to DVA with motor running
did you check the input and outputs of the CDI?

The SM for my motor/year model does not include voltage, but resistance. I did not check the input to the CDI as I though the DVA was not working because the strange measurement.

I did confirm the DVA working so that is why I am confused about the readings.

The reason for testing is I think there is some lack of power at WOT.

I will make some harness to measure the CDI input.

[YamV4130]

https://photos.app.goo.gl/Rg6RYjf8mn2p76Mj9

AC, DC and TRMS measurement from CDI to coil @750rpm

[99yam40]

you must not have a Yamaha service manual.
hard to compare reading to something if they are not in the same type of voltages

[YamV4130]

Output voltage is noted below.

Have not any idea why voltages would be so erratic.
z130cdi.jpg

The reason for erratic voltage was due to I hooked up the CDI output directly to the DVA, disconnecting the coil...thought that was "unloaded" measurement.

The new values are listed bellow...are these high values to any concern? All measurement are done unloaded at cranking expect ignition coil...which was at idle speed, 700rpm.

Pulser coil (both circuits) 5v
Cdi ignition coils 205-210v
Charge coil high speed B/R-L 75v
Charge coil low speed R-BR 230v

High values? Missing some top end power on motor. Runs fine, with no hickups.

[YamV4130]

My reply did not get trough so here it is:



The reason for erratic voltage was due to I hooked up the CDI output directly to the DVA, disconnecting the coil...thought that was "unloaded" measurement.

The new values are listed bellow...are these high values to any concern? All measurement are done unloaded at cranking expect ignition coil...which was at idle speed, 700rpm.

Pulser coil (both circuits) 5v
Cdi ignition coils 205-210v
Charge coil high speed B/R-L 75v
Charge coil low speed R-BR 230v

High values? Missing some top end power on motor. Runs fine, with no hickups

Thank for helping!

[99yam40]

service manuals list minimum peak voltages.
should not be lower than spec

[YamV4130]

I agree!

The SM also states for CDI output "if above specification (peak voltage), replace ignition coil"

Why would the ign coil be the culprit of high voltage? The voltage is produced in the charge coils! The charge coil cant "sense" the ign coil in a CDI circuit?

[99yam40]

the charge coil charges up the caps in the CDI
pulsars tell it when to discharge
not sure on the too high from CDI to ign coil, but think if the ign coils do not bleed it down as it should when discharging it might be a problem with ign coils

[boscoe99]

I agree!

The SM also states for CDI output "if above specification (peak voltage), replace ignition coil"

Why would the ign coil be the culprit of high voltage? The voltage is produced in the charge coils! The charge coil cant "sense" the ign coil in a CDI circuit?

Where in the SM is is it saying that?

[boscoe99]

zll.jpg