Rebuilding my 91 F2 and noticed I have 2 broken intake valve guides. On the Honda parts sites they offer a replacement 12204-MV9-315 GUIDE, VALVE (OVER SIZE). Who can tell me what the oversize means? I'm guessing the OD is bigger, but how much? Does the head need to be reamed before this new guide is installed? Thanks!
The outside diameter is oversized, probably about o.25mm or so. You would need a metric reamer (Honda special tool) for the head and then the OS guide is interference fit. Heat and an installation tool are necessary. You could measure the guide and possibly source a reamer commercially, and you could make an installation tool, but I don't know what machine shop skills you have.