Motorcycle Repair: Kawasaki Vulcan running on one cylinder, kawasaki vulcan 1500a, check oil level

Question
Hi, Mark. My 1994 Kawasaki Vulcan 1500A has 7,000 miles on it and engine oil has been changed a year ago. Used 10W-40 motorcycle oil. The bike is run regularly and one day just started running on only one cylinder. I checked rear 2 plugs and they were wet black fouled. I cleaned them and started the bike, but that cylinder's exhaust was blue oil smoking. Bike did this once before a year ago but cleared by itself. Not making any unusual noises from engine. Everything stock on the bike. Battery is ok but won't hold charge long. Plugs are original.  Rkern@swimusa.com  

Answer
Hi Randy,

Check oil level for proper capacity.

Check cylinder compression. If readings are not within specs, perform a leak-down test. Both tests will determine the condition of the engine's combustion chamber sealing properties. A leak-down will determine which part is causing leak by listening to escaping air.

Oil is fouling rear cylinder spark plugs. If ignition checks ok, piston rings or valve guide seals may be defective and oil fouling plugs.

Respectfully,
Mark Shively