ex500 Gen 1 CDI with Gen 2 engine, ? ignition

[mepasha]

I have a '94 stock engine inside a race pedigree frame. I used a 92 CDI box to run the ignition. I swapped out the alternator cover for a 92 which has the two pickup coils. I also swapped out the flywheel for a Gen 1 flywheel with the single pickup strip.

The bike has spark and will rev out smoothly in neutral. All the wiring seems correct. This is a race bike, so no lights etc. the harness is bare minimum, engine kill switch, tach, coils, CDI. I'm running a total loss system off the battery so no stator. The battery is fully charged. The bike idles like a purring kitten.

However, under load, I am only getting 13 HP on the dyno. The engine has compression. The fuel air mixture from the CR carbs is good across the rev range. It seems like it must be an ignition timing issue.

The bike jumps up to about 12 HP at around something like 2000 RPM, but from there on up it just will not gain power. It just bogs and tries and just brrrrrrrrrruuuuuuuuuuuuuuuuuUUUUUUUUUUUUUUUU up the rev range, but never increases power.

Question: Is there something else I need to do other than swap out the flywheel and pickup coils to match the CDI? It seems as though the timing is not being advanced correctly, but with CDI control, I'm hitting the limit of my wrenching knowledge. Any ideas out there what might cause this situation? Am I even looking in the right place?

[Roofgunner]

Those systems are made to run as a package and without seeing the difference between the two systems it's hard to tell. The CDI box has to be powered in a certain way by the pickup coils, etc to operate. You could attach a timing light while it's running and observe what happens. I would ask whether or not this is a typical modification and has it worked for others. Otherwise, you are breaking new ground here.

[GREENISBEST]

Hi,
This one is interesting

It does sound like an advance problem

Your running a total loss system Have you done away with the Reg/Rect ?

When you swopped out the CDI's how did you rewire the connections as the plugs should be different between these two Models ?

Have you put a Timming light on to see if the marks anywhere near to start with ?

[mepasha]

I agree, it has to be a "package" deal.

I have Generation 1 pickup coils, flywheel, and cdi. My one theory is that maybe the crank and key are degreed differently on the two generations?
If that's NOT the case than I'm at a loss as to why the timing would be off. I've heard from other people that as long as you swap out all three components (flywheel, pickups, and cdi) you should be good to go. Remember that this is a race bike, so don't think street bike harnesses. I have a bare bones wiring setup. I've worked directly from the wiring diagrams to make sure the connections are correct in terms of pickups, ignition coils, tach, power, ground, etc.

I will be putting a timing light on it tomorrow to confirm if it's not advancing correctly and post back the results, but in the meantime...
Another question which may lead to the solution as its a bit more general: what generally causes timing not to advance properly?

[Roofgunner]

The timing is advanced electronically by components of the CDI box after it gets certain signals from the pick-up coil. There are parts called the signal generator, comparator one and two, transistors, etc. The CDI box is more of a potentiameter (sp?) than a computer, like a cars system, in that it's "programed" by it components to behave a certain way to fire the plugs. An interesting study of the advancement of the electronic ignition, is to see how Kawasaki engineers changed, every year, the ignitions on the 500's. By the time they built the 76 500 triples there really wasn't much mechanical stuff. The first 500's had a rotor!!!!!!!!!!!!!! A very good explanation of time and CDI boxes and how they work is in the 1997 Kaw Prairie 400 4x4 manual.

[mepasha]

So I finally got all set up to run a timing light on the bike. Fired it up and within a few seconds realized, with the immediate help of my friend, that it sounded like only one cylinder was firing. Sure enough, the ol' spray bottle on the headers showed that only the left piston was firing.
Lesson learned, never fully trust the dude running the dyno. Not only was the bike putting out low power b/c it was running on one piston, but additionally it was extra low b/c he jetted the carbs for the fuel/air mixture based on this mistake and thus it was running anemic by being super rich!

Grrrrrrrrrr!

Thanks for all the responses.

I'll be doing my own jetting at the track this weekend in preparation for Sunday's race