Dyna S rotor - Either too loose/too tight

[Pendulum]

As the title says, the rotor on my Dyna S is either too tight for me to turn by hand or so loose that the bolt seems like it would loosen after running the engine.

Should I be using Loc-Tite? Greasing the rotor/nut mating surfaces?

[mike_of_bbg]

Hmmm, Those of us with EI bikes have definitely run into the issue of the included spacer being too thick with the Dyna S. The rotor needs to be able to turn independently of the crank when running (so it can advance), but should not be so loose as to be able to slip off of the mechanical advance. The crank end bolt should tighten up against the 17mm nut underneath, and the rotor should have no bearing on its tightness.

If you're using the spacer and it's too tight, you can replace that with a thinner washer of the same inner diameter, or sand down either the spacer or the top of the rotor so the rotor is not captive.

[Pendulum]

I guess I worded my question wrong. What I should have said is that in order the get the end bolt (smaller bolt) tight enough that it doesn't seem like it would back out, the rotor can't advance. Right now it's just finger tight, basically. Any tighter, and the rotor can't spin.

Also, the washer is supposed to go between the rotor and 17mm nut, correct?

[Pendulum]

I might have figured it out...

When I bought the bike, it had a Dyna III ignition. It burned up, so I installed a Dyna S. The rotor from the Dyna III is about 1mm shorter than the rotor from the Dyna S. I'm going to swap the rotors and see what that does.

EDIT: Yep, that was it.