Should I use tread-lock on the pilot nut holding the flywheel on? The guy at the hobby shop said to always do that, but I've been reading a lot of these post and have never seen heard that before.

Thanks

i never use thread lock on any part of my clutch or engine.

If you want use some loctite 222 its soft , generally no but if you feel you need to use just a teeny liddle bit and make sure you dont get it on the bearings ..

I have always used a tiny drop of blue just for safety since having a CB nut work lose during a main.

As long as you don't hit the bearing, you are money.