Super Jet No spark once warm???

[unkwn]

My 2000 Superjet will start fine and run great, once it's well warmed up, I'll kill it and it will not restart. I've checked compression (140 each) but I've discovered I have no spark. If I let the ski set and cool for awhile it'll fire right back up. I've replaced the ignition coil. Had someone bench test the stator and was told its fine...

 

[Tyler Zane]

I really cant think of anything that would cause no spark only when warm. The temp sensor will put it into limp mode but I dont believe it can kill spark all together (I may be wrong). Check your lanyard, and if that checks out and you are holding good voltage while cranking then everything points to your CDI and that s only if your stator and coil are indeed good.

Just curious, how did you bench test the stator? Ohms reading can mislead you, I always check AC voltage output with a DVA.

Is the replacement coil new or used?

 

[OCD Solutions]

My wife's ski did that a couple years ago and it turned out to be a bad charge coil. When it would run, it would run great so I suspected the CDI. I was running a RIVA CDI at the time and switched over to an MSD and did manage to get 3 or 4 more hours out of it before it started doing the same thing. I had JSS go through the stator. He replaced the charge coil and it's been running perfect ever since. Even with a first gen EPIC.

 

[augustaf]

Yes, charge coils can cause the issue of not charging the cdi or enhancer sufficiently when hot. I usually have two in my armamentarium.

 

[unkwn]

I really cant think of anything that would cause no spark only when warm. The temp sensor will put it into limp mode but I dont believe it can kill spark all together (I may be wrong). Check your lanyard, and if that checks out and you are holding good voltage while cranking then everything points to your CDI and that s only if your stator and coil are indeed good.

Just curious, how did you bench test the stator? Ohms reading can mislead you, I always check AC voltage output with a DVA.

Is the replacement coil new or used?

A gentleman I know said he was able to test it if I pulled it, so I'm not quite sure how he went about it.

Ignition coil is new from blowsion.

I have a neighbor thats a shop tech thats going to drop by this weekend and see if we can drop it in and test some things.

 

[OCD Solutions]

Tested a stator today for the same symptoms. Customer said it would start acting up once warm.

All coils were in spec according to my Ohmeter so i threw it on the test bench and ran it up to speed, (I dynamic test at 900, 3100, 5000 and finally 8000 RPM). All coils were outputting within range and it had good spark, even after an hour of running at 3500 RPM. The hottest the stator got was 103F so I helped it out with a heat gun and took it up to 180F. It still idled fine but it dropped 20 volts off all the readings which put it around 107 (PVR) at >6000 RPM. The charge coil needs to put out at least 115 (PVR) to the CDI to get a decent spark, anything less than that and you have to start gapping down the plugs to make it work.

*PVR = Peak Voltage Readings taken using a peak voltage adapter.

 

[augustaf]

The charge coil puts out DC? How do it do that.

 

[OCD Solutions]

The charge coil puts out AC but the only way to accurately measure it is with a peak voltage adapter which reads in DC. So, all peak voltage readings are a DC value. For clarity, maybe I should state the values as PVR (Peak voltage reading) rather than VDC?

 

[Tyler Zane]

Tested a stator today for the same symptoms. Customer said it would start acting up once warm.

All coils were in spec according to my Ohmeter so i threw it on the test bench and ran it up to speed, (I dynamic test at 900, 3100, 5000 and finally 8000 RPM). All coils were outputting within range and it had good spark, even after an hour of running at 3500 RPM. The hottest the stator got was 103F so I helped it out with a heat gun and took it up to 180F. It still idled fine but it dropped 20 volts off all the readings which put it around 107 (PVR) at >6000 RPM. The charge coil needs to put out at least 115 (PVR) to the CDI to get a decent spark, anything less than that and you have to start gapping down the plugs to make it work.

*PVR = Peak Voltage Readings taken using a peak voltage adapter.

I'd love to see a pic of your bench tester! Please?

 

[OCD Solutions]

 

[Tyler Zane]

Thats way too cool man, serious dedication. You can test any ignition component. I wish I lived closer, I bet your whole garage is ridiculous!

Sorry for sealing your thread for a moment OP but I had to ask.

 

[augustaf]

Nice job! All we need now is an event recording oscilloscope to look at the spark- just kidding

 

[OCD Solutions]

The oscilloscope isn't as telling as you would think. At least not the one I was using. Maybe if I learned a bit more about setting up the event triggers?.?.?.

Someday I will invest in a nice digital setup with a recording feature. Being able to capture a complete timing curve would be awesome but its more educational than anything so it's hard to justify the expense.

 

[augustaf]

You are quite correct: " not needed"

 

[unkwn]

That's cool @tzane I was curious too.

 

[OCD Solutions]

Thanks guys, It's a work in progress and I learn something new every time I run it.

 

[550headache]

love the c clamps!