Inner Primary cover extra hole

[WirePan]

Now that I'm tearing into my 55FL (we're having fun now). I noticed an extra (?) hole in the inside primary cover. It's about 3/4" and between the oiler and the clutch.
Nothing is hooked up to it (or going in it).
Anyone know what it's for?
Should I plug it?

Thanks!

[DuoDave]

My guess is that the hole is there to run an extension tube from the engine breather to the outside world. This does not do much for the life of your primary chain, but it does stop oil collecting in the chaincase and dripping on to your driveway or garage floor. I just use a drip tray. If your bike has been converted to a belt primary, then it's almost a certainty that this is why the hole has been drilled.

[WirePan]

Thanks DuoDave!
The hole is about mid way between the Oiler and the transmission and is right in the middle of the cover so it's too high to be a drain for the primary. The original drain is still below the clutch.
I think I'll just plug it for now (repair later).

[stiggyc]

I have it too on my '55. If you have the stock oil breather tube with the offset, , the part where the 90 degree bend is interferes with the inner primary and it cout out for in to fit in. And it picks up road dirt. I run a bead off oil resilient RTV and it help keeping the mist oil from dripping out. Works for me and I've done that trick for 20 years.

[WirePan]

Thanks Stiggyc!
That must be it!

WirePan