There is a thick oily residue around the exhaust hole on a 96 GSX that I am looking at buying. Is this normal? The engine was rebuilt and converted to premix. Does it mean that the mixture is too rich?
It could be, check the spark plugs to be sure. Sometimes the extra oil is from it being premixed as it has the same amount of oil burned at all different rpm's with the injector oil is injected at a variable rpm's as needed so it burns less.