Lightening the flywheel:)
Ok, the other day I was lightening a flywheel for a customer. Now...I've done about 12 of these over the past few years, and when I set them up on my lathe I always indicated the center bore to make sure it's at zero run out. Here's what i have found on a couple of KLX flywheels(including my own) they are NOT concentric. Meaning the center bore and the outside diameter are a bit out of wack....about .007 to .009 thousandsths of an inch. Now this would explain why my KLX had a slight vibration at 5k rpm. So, not only did the 1lb. of material that I took off the flywheel help the motor rev up quicker but the annoying vibration is now gone as well.
Yes it's a manufacturing flaw on some of the flywheels. The flywheel backing is riveted onto the magneto rotor, and if everything is not lined up 100%perfect...then you have what we got here. To just true it up, it would only take less than half an ounce of material to be removed.
You don't lose any of the tractor-like feel, but what you do gain is a little bit more throttle response.....since there's less weight to spin quickly.
Hmmm.. I may have to try this. I'm going to try to source an extra flywheel so I can have both.. I'll be in touch 
EDIT - what am I talking about? I forgot I have an extra entire bottom end... I am going to pull that flywheel. I will shoot you a message when I have it off to see where to send it.
Thanks!

EDIT - what am I talking about? I forgot I have an extra entire bottom end... I am going to pull that flywheel. I will shoot you a message when I have it off to see where to send it.
Thanks!


