I have an FMF Mega Bomb header on my '06 YZ450F. I just finished doing the bearing in the filter drain hole mod and hooked everything back up and did the usual party dance, revved the motor and all that happy stuff:banana: I noticed that the header out of the top end pushes out (moves about a 1/4" or so; I don't think I ever noticed this before. Is the aluminum spacer on wrong, do I need high temp silicone prior to mounting? Anyway, i obviously have a loose connection there as it is backfiring. Maybe just tighten?