no spark #3 cyl. on '88 90hp

[imadan]

howdy,
looking for some help troubleshooting a 90ETLG. no spark on #3 cyl. initially found secondary windings open on that coil, so replaced it and still no spark. swapped coils around and no change. borrowed a peak reading voltmeter and found no output from the CDI on post #10 (#3 coil). output for #1 & 2 were both 190v at 1000rpm. charge coil and pulsar coil voltages both within norms.
local yamaha tech said warning system activation would drop out one cylinder to reduce rpm's. i tried running motor with pink wire disconnected from CDI thinking it would isolate the warning system, but no still no spark on #3 cyl. also, this motor had the oil injection system previously removed and has a plug disconnected from the oil injection CONTROL UNIT. the motor will produce 3000-3500 rpm under load without #3 firing. shouldn't the warning system limit rpm's to around 2000 rpm? additionally, the warning buzzer does not operate. i apologize for the lengthy post, just trying to provide all the info. thanks, dan

[boats.net]

Based on what you said you have a bad CDI unit, your test rulled out the rest of componets.

[imadan]

thanks for the reply, just want to be as certain as possible before making the big purchase.

[99yam40]

how many charge and pulser coils does it have that you tested?

I thought I read somewhere that some 3 cylinder motors have 2 pulser coils that tell different cylinders when to fire, but I an not sure about that.

And I was thinking that I read that open coils may cause high voltage kick back spikes that will damage the CDI's.

[imadan]

howdy,
this model has two pulsar coils, each with separate wires going to the CDI. i had access to a known good pulsar coil assembly and everything checks exactly the same between the two.
the charge coil also had good resistance readings and good readings from the peak voltage meter. my understanding is that a fault in the charge coil would affect all 3 cyl's not just #3. is that correct?
could the bad coil i previously changed out on #3 cyl. have damaged the CDI?
dan

[99yam40]

What ohm and voltage reading did you get on the pulsar coils and the charge coil?
If there is only 1 charge coil then it would have to be for all cylinders. With 2 pulsar coils you need to make sure both are putting out correct voltages

Like I said, I read somewhere that bad coils can cause Problems with CDI.

[imadan]

howdy,
the readings on the pulsar coils were: w/b to w/g 380 ohms, 9v.
w/r to w/y 370 ohms, 13v.
charge coil readings were: brown to blue 880 ohms, blue to red 120 ohms,
brown to red 1000 ohms. blue to red 150v, red to brown 170v.
all peak voltage readings were taken "connected" and at 1000-1200 rpm.
my repair manual is a seloc that covers 1984-88 3cyl. models and gives only resistance/ohm values, but the local yam tech thought my peak voltage readings were in the normal range. dan

[99yam40]

pulsar coil at 13v looks kind of high and manual says replace CDI if beyond spec. and if you are not getting any out put from CDI to #3 coil then looks like you need to spend the money for a new one.

[imadan]

thanks for the replies! i'll update the post after the cdi is replaced.