[C.C.]

I thought the hole helps the oil have one more place to leak out. Just kidding but I do get some seepage out of mine.

CC

[GreenMachine]

i get a wee bit of red type 4  seepage out of mine too...Just a swipe of a cloth takes care of it...

[greekxj]

Ya mine seeps also with the ATF Type F in there. If i go for a good ride and things get nice and warm ill have a little red line running down. Maybe it happens easier with the ATF because of the thin viscosity compared to a 20w50 etc. Ah well i just wipe it also and live with it. I have the 800 ML in there too.

[tooseevee]

       Not an iron barrel, but my '08 AVL's primary case is vented out the top into a small hose that used to go to "the can". All that stuff is gone now & I turned the elbow forward & ran the hose down between the case & the starter motor & cut the excess off. Maybe some day I'll tap the hole & drill a small hole in the plug. Back in the day when some engines & the primary cases shared oil (stupid idea), there was a small vacuum on the primary case to help reduce leaks at the gasket.   

[barenekd]

Back in the day when some engines & the primary cases shared oil (stupid idea), there was a small vacuum on the primary case to help reduce leaks at the gasket.    

Back in the day? Most engines nowadays share the oil in the engine, transmission, and primary drive. That's why there is motorcycle specific oil. There is no real division between the three like there used to be. Early Britbike unit construction designs were the ones that had separate oil supplies, although the BSA/Triumph engine crankcases did breathe into the primary case and that's where the breather exited. Modern engines, including the UCE RE engines, share the oil and the breather comes out of the timing side case. Apparently, the AVL engines are more like the Tri/BSA setup.
Bare

[GreenMachine]

I have 800 ml in there too and experience the same thing after a long drive...although my yamaha and hyosung uses the same oil for the engine and transmission I never like the idea of sharing lubricating properties  but  it seems to be the norm..