Gpz550 ignition advance more power!?

Hi, now that my motor runs properly, is there a mod for tuning the igniton.
The ignition plate holes are not slotted so should I slot them and if yes what to do with timing.
Regards David

First you have to verify where the timing is, and the advance curve. If it is the same as stock, then you have nothing more to do. The advance curve is in the manual. SO you will need a timing light and a really precise tach. The bike's tach is usually not precise enough if you really want it accurate.

With a Gpz motor, you do not want to go any more advance than stock. Stock motors will even get a little knocking on highway acceleration if you are not careful with the throttle and downshift when needed.

I remember a magazine story from the day where they took the timing plate out of an '81, found the right size die-grinder bit and made theirs adjustable, advanced the timing two degrees, and shimmed the needles .034", and they were rewarded with almost a whole horsepower on the dyno - 56hp - not much return for the work -

GPzEric wrote: I remember a magazine story from the day where they took the timing plate out of an '81, found the right size die-grinder bit and made theirs adjustable, advanced the timing two degrees, and shimmed the needles .034", and they were rewarded with almost a whole horsepower on the dyno - 56hp - not much return for the work -

...And at what cost on longevity... not worth it.

The later ZX550 motors do advance the ignition more at higher RPMs, but also have a more gradual curve initially (done electronically, not mechanically). It's that early advance, at the lower RPMs, that does the damage with the mechanical advance curves.

Is it possible do use a modern CDI zr750 ignition on old mechanical advance KZs?

loudhvx wrote:

GPzEric wrote: I remember a magazine story from the day where they took the timing plate out of an '81, found the right size die-grinder bit and made theirs adjustable, advanced the timing two degrees, and shimmed the needles .034", and they were rewarded with almost a whole horsepower on the dyno - 56hp - not much return for the work -

...And at what cost on longevity... not worth it.

The later ZX550 motors do advance the ignition more at higher RPMs, but also have a more gradual curve initially (done electronically, not mechanically). It's that early advance, at the lower RPMs, that does the damage with the mechanical advance curves.

And that's why I recurved the timing on my 1000.

.

The mechanical advance definitely is a compromise between ideal advance at higher RPMs, and saving the motor from knock at lower RPMs.

The analog electronic advanc is better,but likely is also a compromise. The best is probably digital advance, as in the more expensive Dyna products. The down side is that they cost a lot, and don't seem to be as reliable as the factory units.

The pickups for the later factory, analog-electronic-advance may fit into the KZ750 motors, but I'm not sure. I know on the KZ550's, it's close but does not fit without making some alterations to the case castings. (The KZ550, 650, and 750-fours used the same size pickups andtiming plates.)

Incidently, non of the above is actually CDI. They are all transistorized Kettering, AKA flyback, and sometimes referred to as simply "inductive".