spark timing curve

[jaguar]

I just found out that there's a PVL ignition for some KDX's that increases spark strength. Its a complete ignition system replacement and for my 89 only the analog system which doesn't support lights is available. The timing curve is viewable at http://www.mxsouth.com/pvl/pvlign.htm and I was wondering what the stock system is ilke. Does it advance or retard the spark as rpms increase or does it keep the same timing throughout? Anyone ever use a timing light to watch what timing changes there are as the engine is revd?
just curious

 

[G. Gearloose]

The stator's initial is heavily advanced, and the box provides significant retard.
As rpm's increase, the retard is reduced, essentially providing advance. its done by 5-6 grand.
Clear? :eek:

 

[jaguar]

How would you say the stock curve compares to the analog graph at the site I listed?

 

[canyncarvr]

I thought (recall having read someplace) that there is a significant retard about the time the KIPS comes on. It's a significant drop.

Actually, I'm quite sure that's in the service manual.

re: Initial advance, retarded by the box.

Any one ever wondered how it is the box could advance a mechanical spark?

Answer is, it don't.

;)

 

[jaguar]

hmm, my manual lists 19 BTDC at 6000 rpm.
good point on the inability to advance the timing. It must just be able to retard it.
Canyon, surely you have put a timing light on your bike to see what the timing does as you rev it?

 

[canyncarvr]

Surely you might think that!

But....alas. Having no ability to adjust it excepting for initial timing, I must say I really don't care much! :(

An inquiring mind may well want to know if only from the standpoint of understanding the issue or maybe modifying the curve for improved performance.

As I say.....alas! Guess that's not me! ;)

 

[jaguar]

hey, you're better off just being practical. Us curious types get into a lot of trouble!