clutch insert/clutch adjust?

[VictorK]

I have a billet insert now and it has orings behind it. The reason must be so I can drill a hole to adjust the clutch, if that's true how big of a hole do I drill and where exactly does the hole go, in the middle?

[AKheathen]

the o-ring behind the cover is dual puropse. first- without it, the insert will eventually, or even immediately, start to rattle/tap like crazy making you chase your tail trying to find the sound, and 2nd- it should seal it up, like you are thinking, to be able to drill the hole to adjust the clutch. i think it's like a 1" hole as the origional mod was done, but i hear it's a tad tight. really, you can go big as you need to get a wrench and screwdriver in there to adjust it. the adjuster is right in the center.