Cdi red white wire ?

[Mwrunt]

I have a 91 superjet that is pretty much stock.
Lately I have been having some possible electrical issues.
Ski runs fine until u it is subbed and then starts to run crappy. I am assuming water is effecting somthing or maybe the coil and cdi are acting up when warm. So I left the ski on the trailer and swapped out the cdi. But the 62t cdi has a differnt end on the wire wire with red strip.
I fired up the ski and the stumble is gone and it revs clean all the way through.
Once I connect the red striped wire the rev limiter kicks in.
Is it bad to run it this way.

 

[OCD Solutions]

I must be missing something...the white wire with a red stripe should be the pulse coil and the ski should not run without it connected.

 

[Mwrunt]

Ok weird. Just put the 61x cdi back i

I must be missing something...the white wire with a red stripe should be the pulse coil and the ski should not run without it connected.[/QUOT

 

[Mwrunt]

Ok weird. Just put the 61x cdi back in and it runs with out the hesitation to wit the wire disconnected

 

[OCD Solutions]

Dirty or loose connection?

 

[Mwrunt]

That's a thought to. Is this the pulse coil

 

[OCD Solutions]

Yes. They normally have a blue wire though. Has that been replaced with a WSM unit?

 

[Mwrunt]

It's a new spare that came with a ski I just bought. It had no box so probably a wsm or sbt unit.

 

[OCD Solutions]

Okay, so that's a spare and not the one currently in your ski right?

 

[Mwrunt]

Ya not in the ski. Came with a differnt ski.

 

[OCD Solutions]

Alright, I didn't believe it so I mocked it up on the test bench and guess what? The ignition will fire with the white/red wire disconnected!! This is with all known good components too so it's not an anomaly due to a failed component either. So, if connecting up the white/red wire causes it to hesitate, I would print off the pages of the service manual I posted above and meter out the stator, particularly the pulse coil. If you have time, maybe swap in that spare stator and see if it improves.

 

[Mwrunt]

which ecm would you say is better 62t or 61x or 6m6 with rev limiter removed

 

[OCD Solutions]

Curve wise I believe they are all comparable other than the rev limits. The 61X has a single magnet flywheel so it might offer a slight advantage in rotating mass as well as an even slighter advantage by having less magnetic resistance.

That being said, I don't think the majority of riders would ever feel a difference from one to the other, (other than pegging the rev limiter).

 

[Mwrunt]

thanks for the info and help. I am going to put both skis back together tomorrow and see what happens I will also try run without the red stripped wire
I didn't ride the ski today I just ran it on the trailer with the pump in the water to see the difference. so if I can get it on the water before dark I will post the results

 

[OCD Solutions]

Yes please on your results. I'm real curious to see how it runs without the pulse coil connected.

FYI, the capacitor will still discharge and the CDI will output a spark but you won't have a curve; It'll just be a flatline. I didn't break out my degree wheel to see where the actual timing will be in relation to static timing but it must be close if it's able to fire and run. At 3500rpm, there is a 10 deg difference between the timing mark with the white/red wire connected versus disconnected.

 

[Mwrunt]

Ya it runs clean through full rpm with it disconnected.
With it connected it is clearly hiring the rev limiter.
I remember when we hoped up a yamaha scooter for a pit bike we unplugged a wire to disconnect the rev limiter I wonder if these cdi units work the same.
Here's the info on removing the yamaha scoot rev limiter

 

[zimmy]

So, all those CDI rev limit bypass projects could have been completed by just unplugging the red/white wire from the stator? Or did I completely miss what is being said here...

 

[OCD Solutions]

It might get you by in a pinch if you don't mind running a flat curve but it will be less than ideal.

Initial testing indicates that the charging coil is capable of producing a spark all on its own and the purpose of the pulse coil is simply to provide feedback for all rpm related tasks like rev limit and adjusting timing advance.

 

[zimmy]

Gotcha

 

[Mwrunt]

My suspicions are the pulse coil runs off the ground through the engine and both wires just provide a negative signal. White wire with red strip probably controls timing and rev limit and the other wire possibly triggers the discharge for the coil.
But who knows it could be like the scooter ignitions yamaha used in the past and the red and white wire controls just the rev limiter. And people have been spending money to get the limiter removed for no reason.
It would be nice to see someone check the timing curve with the wire disconnected