RE: Losing a quart of oil every 100 to 200 miles

First and foremost as suggested would be a compression test.  This would give you some idea of which cylinder may be suspect. A more decisive test would be what is known as a leak down test. Although this is a simple task that can be performed by a novice, extreme caution should be used.  Using your compression tester hose insert it into the suspect cylinder spark plug hole.  Place the motorcycle on its center stand if it has one. If not, employ the help of a friend.  Remove the timing cover located on the engine case and find the marker for top dead center.  If #3 cylinder is suspect turn the engine over by placing it in 2nd gear.  With the bike on its center stand either turn the back wheel manually in the forward direction until the piston in the #3 cylinder reaches top dead center on its compression stroke or if you do not have a center stand or means of lifting the bike, roll the bike on its wheels until the #3 piston is almost to top dead center.  You will know if the #3 piston is on its compression stroke as compressed air will expel from your compression tester hose. At this point, gently turn the rear wheel very slowly until the exact point of top dead center is reached.  At this point have your helper apply plenty of pressure to the rear brake in order to keep the rear wheel from turning.  At this time couple your air supply, maximum of 120 psi, to the compression tester hose.  Slowly open the air valve, applying air pressure in the cylinder.  If all goes well and you can maintain top dead center it will become apparent whether your problem is in the valve train system, (ie: valve guides, worn valve stems or perhaps a valve guide seal has either come off the valve guide or in a lot of cases have developed cracks in the seal).  Or if the problem is with the piston rings it could be due to excessive wear, cracked or broken rings beyond tolerance end gap and in some cases piston ring slap.  The latter being the clearance between the ring and piston groove. Compressed air leaking out of the crank case vent would suggest that the problem is the piston and ring combination.  Compressed air leaking back into the valve train galley of course would  suggest the problem lies in the valve train system.   Compressed air leaking into the intake track and into the carburetor, I would direct my attention to either bent or burned or improperly adjusted valves.  Compressed air leaking into the exhaust track and exhaust pipe would give a strong indication of improperly adjusted valve clearance, bent valve or burned valve. All of these conditions can be aggravated by long term storage.  Long term storage can cause buildup of rust in the cylinders which leads to broken rings and excessive wear on the pistons.  Also rust on the valve stems can cause the problem with the valve train.  Please remember to remove the ground cable from your battery before starting any test.