Actually, a blown head gasket will leak that much oil, as that is where the oil passages go through in order to lubricate the camshafts. I had a similar problem on my old Suzuki GS650GL. a new head gasket solved the problem.jonnythan wrote:
I'd be surprised if a blown head gasket led to that much oil leaking, because the head is where the gasoline gets combusted so there's little to no oil up there.
If the oil seems to be leaking out more at the front near the base of the cylinder, then it could be the cylinder base gasket is shot, or, as storysunfolding mentioned, it could be the oil filter cover is leaking - also not an uncommon occurrence.