SV flywheel rotor lightening

One for the techies here... I'm interested in lightening the rotor flywheel on my K5 race bike as done by Spears Enterprises in the US. A friend of a friend has a lathe and a method of balancing the flywheel. Anyway, here's the problem...

As can be seen from the pics there are raised lugs and a small countersunk 'dimple' on the outside of the flywheel. The crank position sensor incorporates two pick-ups, both with their own separate wire(s), one a single metal bar which reads the lugs and the second a twin bar which presumably reads the dimple. It has been suggested to me that the dimple is for balance but, as the lightening involves machining the flywheel back to the lugs and no more dimple, I need to find out what this second pick-up is for. Any gurus out there can shed the light?

who told you it reads dimples?it does not,only lugs.
if you taking magnets out you can cut it all the way up to lugs.

The fact that the second pick-up in the sensor, which is aligned with the dimple, and with it's own wire, leads me to believe that it has some significance.

Originally Posted by Tirofog

The fact that the second pick-up in the sensor,

that is not the fact

So both of the pick-ups contained in the sensor read the lugs only??

[TSM]

Originally Posted by zadar

that is not the fact

if that is a 2nd pickup, could it be used as a reference signal compared to the lugs? just wwandering, or there is the possablility that its not used on the SV.

I would say that the dimple is not big enough for any balancing purpose. But it could possibly be a timing mark.

Originally Posted by TSM

if that is a 2nd pickup, could it be used as a reference signal compared to the lugs? just wwandering, or there is the possablility that its not used on the SV.

That's what I was thinking, if it's for the FI or something a bit obscure which wouldn't stop the bike running, then any effect may not be that obvious after the flywheel is lightened and no dimple..

Originally Posted by Tirofog

That's what I was thinking, if it's for the FI or something a bit obscure which wouldn't stop the bike running, then any effect may not be that obvious after the flywheel is lightened and no dimple..

frist at all there is no second sensor.second,that dimple you talking about is just dot like stamp mark or tip of drill.sensor is nowhere close to it.what you believe is second sensor is actually just plate showing through.and even if it was sensor it would read on other side of lugs,back not front.
now those indentations on back of flywheel are to locate magnets on inside of flywheel.

Good stuff... thanks for clarifying that, appreciate the help.