I would think if it were a valve seal dumping 1.5qts every 200 miles that bike would be blowing a blue cloud of smoke from the exhaust outlets. It would also have wet tips on the mufflers (wet with oil).So I just bought a 96 Ducati 900ss and I’ve noticed I’ve been eating up oil. 3 days ago I checked it in the sight glass and was normal level. Took it maybe 200 miles max and now it’s not even registering in the glass. Took about a quart and a half to even get it to show on the sight glass so I’m assuming it was dry yikes. The ONLY place I see minor oil leak is coming from the front exhaust header flange has a slight drip. Valve seal? How can I tell if the valve seal is bad? What else should I check? I am occasionally getting white smoke out the exhaust. Also idle is choppy and when I was riding the other day i has loss of power in 5th at high speed, if I feathered throttle it was ok and if I gave it hell just bog. I dont know if the oil loss is related but I want to take care of oil loss first.
Keihin FCR 41 carburetors
CCA performance coils
CCA Timing belts
Shori lithium ion battery
Superlight sprocket kit 42/15
DID ZVMX Chain
Oberon Clutch Slave Cylinder
EBC Brakes front and rear
Strada fab full titanium exhaust
Pull the horizontal cylinder's spark plug and take a look at the plug. If it's wet/fouled then at least some of that oil is making it's way into the combustion chamber, one way or another (cracked head? ... fekkered head gasket? ... loose valve guide? ... other?).
Hopefully more experienced members will chime in soon.