Bad CDI

[jjsinaz]

Well, just when I thought there wasn't anything else to go bad on this damn thing, now it appears that the CDI unit has failed. It ran the last time out which was about a month ago, but whenever I went to start it the other day, no spark.

I am getting pulses from the trigger coil and the main ignition coil appears to be okay. There appears to be some voltage pulses coming out of the CDI in the white wire to the coil, but they seems very low (tenths of a volt). Resistance readings on the CDI unit also lead me to draw the conclusion that it is the culprit. Resistance between the white wire and black wire should be around 2.2 M ohms but I am getting an infinite reading.

What would be a reasonable price to pay for a used CDI unit? Anybody have one they want to sell?

 

[WhiskeyD]

What model ski? I've got CDIs for 787s

 

[jjsinaz]

1996 only I believe. 97 they went to the integrated MPEM. Well, I put everything back together and it has spark and runs now...go figure. Hope I don't get stuck on the water. That was the only good thing about this...it happened at home in the garage

 

[jjsinaz]

It's a 1996 GTX. I'm about ready to say to he11 with this sport/hobby. I spend more time f@#king around with this thing than I do riding it. Just not fun anymore.

 

[WhiskeyD]

I've got quite a few tested and working 96 CDIs. Have a couple of the 97 cdi/mpem too. PM if you end up needing one and I'll match whatever they are going for on eBay

 

[jjsinaz]

Thanks Whiskey. I appreciate that!

 

[jjsinaz]

Just an update on this problem.

I took the ski to the lake on Saturday and it ran good all day. Brought it home, parked in the garage. Yesterday I went to start it and it would try to start but quit. Today I tried again and it seems that it will start and run until as long as the start/stop button is depressed but will quit as soon as the start button is released, or very shortly thereafter. Anybody else ever had this experience or similar?

 

[jjsinaz]

Okay, I checked the start button and it appears to be okay. Wiring between the s/s button and the ECU appears okay. Voltage going to the CDI module from the holder relay is okay. It's looking more and more like a bad CDI. Are these prone to failure? I do realize it's 22 years old and nothing lasts forever LOL

 

[jjsinaz]

Been thinking about this a little deeper. Checked the voltage going to the CDI while cranking and it's only about 9.4 volts. Last time, it started working again after I had charged the battery up because it was very low due to all the cranking trying to get it started when it had no spark. Ran good after that, but after sitting for a few days, problem returned. Thinking maybe it's time for a new battery. The one I have is about 2 years old now and batteries don't last very long in AZ due to the heat.

 

[Mekanix]

This has low voltage while cranking all over it
I think your cdi is fine and it's just the load is reducing the voltage below what's needed for the 96 system. Swap over to a 97 unit and you wont have as much trouble but for this just get a good ytx20hl-bs battery or equivalent 310cca+ battery and you should be good.
210cca isnt enough, even 270cca at times isnt enough either when you factor in resistance of the wires and terminals and high load on a battery that has been sitting for a week. When you see 11v or lower at the battery, the cdi usually sees less than 10 and just will not charge enough, but like you saw with the pulses it is trying to trigger still.

Oh and the resistance values are never right.

 

[jjsinaz]

Thx Stephen. I was kind of thinking along the same lines, so I appreciate your feedback.

 

[jjsinaz]

Well, I replaced the battery with a new one. Cranks over like mad but no spark. Tried running a direct wire from the battery to the red wire on the CDI, bypassing everything else, still no spark. Even pulled the mag cover off to make sure the trigger coil bracket wasn't broke. I am to the point where I believe the CDI is the only thing left. WhiskeyD, check your mail I pm'ed you

 

[jjsinaz]

It's Alive! Bought a used CDI. This fixed the problem