Digital CDI failures

Watty

Random Performance
Location
Australia
Guys,

A quick question for anyone that cares to comment.

My 98 Superjet seems to have always had problems with digital CDI's. The stock one has always worked flawlessly from day one.

To date, I would have been through at least 10 different digital CDI's, with all bar one failing on me. The only one that worked for me was a Vilder, whcih I sold as I didn't have the ability to re-program it as I constantly changed my setup.

Ok, so I figure it's something in the electrical system, fine. I replace the coil with a brand new oem coil, with new oem (style) wires. I replace the flywheel with a new one, and also a stator with a new one, so basically I have a whole backup ignition system. I use resistor plugs, and resistor caps, so what else is left?

The CDI's seem fine initially, and generally run great. One brand would fail after about 10 minutes, and the other would last maybe 3 hours.

I guess my question is, what else could be causing these failures, or is it just a simple case of the ignitions themselves not being up to the task? I find it very hard to believe that 2 sets of stator/flywheel/coils could be bad, or bad enough to kill an ignition.

I know the Superjet electrical systm is old and outdated, but is it really that hard to get a clean ignition pulse?

I have a pretty nice setup, but so far, I have been unable to see the best of it, as I've kept my compression quite low due to the stock CDI holding more advance up top than what I'd like when running 195psi. The inital advance that the stock CDI holds is also minute, and sees my engine mods being all but wasted.

Does anyone have any ideas? I'm seriously thinking about a new total loss system just to eliminate EVERYTHING with the stock system.
 

dawson

X
Location
down under
the digital ignitions are very sensitive to electrical noise.
are you running resitive leads ?
resitive plug caps
resistive plugs
you should probabley be running at least 2 of the above for proper noise supresion to protect the sensitive components in side the ignition module.
i work for a company that manufactures and services ignition systems for industrial gas engines wich are far more complex than the basic jet ski ignition
if you are running 2 of the above and still cooking cdi's i will talk to some of the engineers here at work and see what there opinion is
 

Watty

Random Performance
Location
Australia
Ok, so I figure it's something in the electrical system, fine. I replace the coil with a brand new oem coil, with new oem (style) wires. I replace the flywheel with a new one, and also a stator with a new one, so basically I have a whole backup ignition system. I use resistor plugs, and resistor caps, so what else is left?

G'day Dawson,

Yep, I run hurricane ignition leads, resistor caps and plugs. I also use iridium plugs as well (only recently)

If you have any other ideas, I'm all ears!

Leigh
 

dawson

X
Location
down under
well the only other thing i can think of is the coil or a bad earth between the coil and cdi box wich can cause spikes to go into the ignition box
is it a stock coil
i have had customers blow ignitions due to using the wrong coils on there ignitions ( this is industrial ignitions )
other wise i am stumped and sorry for giving you faulse hope

there are people alot smarter than me out there so hope one of them can help
best of luck
 
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